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A teaching tool for architectural acoustics

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A teaching tool for architectural acoustics

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Content A TEACHING TOOL FOR ARCHITECTURAL ACOUSTICS

by

Tianxin Xing

A Thesis Presented to the
FACULTY OF THE SCHOOL OF ARCHITECTURE
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
MASTER OF BUILDING SCIENCE

May 2009

Copyright 2009 Tianxin Xing
ii
Dedication
This thesis is dedicated to my parents and my wife who supported me all the way
through my study in University of Southern California.
iii
Acknowledgements
This thesis could not have been accomplished without Professor Marc Schiler who not
only served as my committee chair but also guided me through the academic program.
He and the other committee members, Professor Doug Noble and Professor Murray
Milne, encouraged and challenged me throughout my study process, never accepting
less than my best efforts. I would like to extend my heartfelt gratitude to all of them.

iv
Table of Contents
Dedication ii
Acknowledgements iii
List of Figures vii
Abstract xiii
Chapter 1. Introduction of the AATT 1
1.1 Introduction 1
1.2 Hypothesis 3
1.3 The Importance of the AATT 4
1.4 Hypothesis Explanation/Elaboration: Terms 5
1.4.1 Sound Absorption 5
1.4.2 Reverberation Time 6
1.4.3 Transmission Loss 8
1.4.4 Other Important Terms 9
1.5 Hypothesis Explanation/Elaboration: Study Boundaries 9
1.6 Hypothesis Explanation/Elaboration: Scope of Work 9
1.7 Chapter Structure for what is coming next 10
Chapter 2. Introduction of Architectural Acoustics and Acoustics Software Tools 12
2.1 Introduction to architectural acoustics 12
2.2 Existing Acoustics Software Tools 18
2.2.1 A brief description of EASE 18
2.2.2 A brief description of NEMPEE Acoustics Software 19
2.2.3 A brief description of CATT-Acoustics 21
2.2.4 Other Acoustics Tools 22
Chapter 3. AATT programming 25
3.1 The main book used for making the program 25
3.2 The tool for writing the program 26
3.3 The structure of Architectural Acoustics Teaching Program 28
3.3.1 Basic Theory 29
3.3.2 Sound Absorption 32
3.3.3 Room Acoustics 33
v
3.3.4 Sound Isolation 37
3.3.5 Electronic Sound Systems 37
Chapter 4. AATT Program Tutorial 39
4.1 Interface 39
4.2 Basic Theory 42
4.2.1 Frequency, period and Wave length 43
4.2.2 Sound Intensity 47
4.2.3 Sound Intensity Level 49
4.2.4 Loudness 50
4.2.5 Noise Reduction 51
4.2.6 Decibel Addition 52
4.3 Sound Absorption 53
4.3.1 Sound Absorption Coefficient 54
4.3.2 Noise Reduction Coefficient 55
4.3.3 Room Noise Reduction with Treatment 55
4.4 Room Acoustics 57
4.4.1 Sound Reflection, Diffusion and Diffraction 58
4.4.2 Initial Time Delay 59
4.4.3 Reverberation Time 62
4.5 Sound Isolation 65
4.5.1 Transmission Loss and STC 66
4.5.2 Mass Law 66
4.5.3 Noise Reduction between Rooms 67
4.6 Electronic Sound Systems 69
4.6.1 Basic Elements 70
4.6.2 Loudspeaker Systems 72
4.6.3 Electronic Background Masking Systems 75
4.6.4 Summary 75
Chapter 5. AATT Program Debugging 76
5.1 Introduction of the debugging Method 76
5.2 First Part of the Debugging 76
5.2.1 AATT package 76
5.2.2 AATT installation 78
5.2.3 Navigation Test 81
5.2.4 Input Test 81
5.3 Second Part of the Debugging 94
vi
Chapter 6. Conclusions of this thesis and Future Work on AATT 98
6.1 Conclusions 98
6.2 Future work 101
Bibliography 103

vii
List of Figures
Fig. 1-1 Animation of Initial Time Delay 1
Fig. 1-2 Calculation Function-Frequency Calculator 1
Fig. 1-3 Sound Example-Loudness 2
Fig. 1-4 Interactive Graphic-Reverberation Time 2
Fig. 1-5 Video of Sound Reflection 2
Fig. 1-6 CATT-Acoustics Program 4
Fig. 1-7 Program Structure 10
Fig. 1-8 Error Checking 11
Fig. 2-1 EASE Program 19
Fig. 2-2 EASE Program 20
Fig. 2-3 EASE Program 21
Fig. 2-4 CATT-Acoustic Program 22
Fig. 3-1 Program Structure 25
Fig. 3-2 Visual Basic Interface 27
Fig. 3-3 AATT Interface 28
Fig. 3-4 AATT Greeting Interface 28
Fig. 3-5 AATT Main Menu 29
Fig. 3-6 Basic Theory Interface 30
viii
Fig. 3-7 Period Calculator 30
Fig. 3-8 Sound Frequency Interface 31
Fig. 3-9 Sound Example in Different Frequency 32
Fig. 3-10 Sound Example in Different Loudness 32
Fig. 3-11 Sound Absorption Interface 33
Fig. 3-12 Room Acoustics Interface 34
Fig. 3-13 Animations of Sound Reflection, Diffusion, and Diffraction 34
Fig. 3-14 Video of Sound Reflection 35
Fig. 3-15 Reverberation Time Calculator 36
Fig. 3-16 Interactive Graphics for Reverberation Time 36
Fig. 3-17 Sound Isolation Interface 37
Fig. 3-18 Electronic Sound Systems Interface 38
Fig. 4-1 Program Interface 39
Fig. 4-2 Second Interface 40
Fig. 4-3 Main Menu 41
Fig. 4-4 Program Instructions 42
Fig. 4-5 Basic Theory 43
Fig. 4-6 Sound Frequency 44
Fig. 4-7 Sound Frequency 2 45
ix
Fig. 4-8 Sound Examples in Different Frequencies 46
Fig. 4-9 Period and Frequency Calculators 47
Fig. 4-10 Sound Intensity Introduction 48
Fig. 4-11 Sound Intensity Calculator 48
Fig. 4-12 Inverse Square Law Introduction 49
Fig. 4-13 Inverse Square Law 49
Fig. 4-14 Sound Intensity Level Introduction 50
Fig. 4-15 Loudness Introduction, 51
Fig. 4-16 Sound Examples in Different Loudness 51
Fig. 4-17 Noise Reduction Introduction 52
Fig. 4-18 DeciBel Addition 53
Fig. 4-19 Sound Absorption 54
Fig. 4-20 Sound Absorption Coefficient Introduction 54
Fig. 4-21 Noise Reduction Coefficient Introduction 55
Fig. 4-22 Room Noise Reduction with Treatment 56
Fig. 4-23 Room Noise Reduction with Treatment Calculator 57
Fig. 4-24 Room Acoustics 57
Fig. 4-25 Sound Reflection, Diffusion and Diffractio 58
Fig. 4-26 Sound Reflection Video 59
x
Fig. 4-27 Initial Time Delay 60
Fig. 4-28 Ray Diagram 61
Fig. 4-29 Initial Time Delay Gap Calculator 61
Fig. 4-30 Reverberation Time, 62
Fig. 4-31 Reverberation Time Calculator 63
Fig. 4-32 Reverberation Time Result Graphic 63
Fig. 4-33 Sound Examples in Different Reverberation Time 64
Fig. 4-34 Sound Examples- Talk 64
Fig. 4-35 Sound Examples- Music 65
Fig. 4-36 Sound Isolation 65
Fig. 4-37 Transmission Loss and STC 66
Fig. 4-38 Mass Law 67
Fig. 4-39 Noise Reduction between Rooms 68
Fig. 4-40 Noise Reduction Calculator 69
Fig. 4-41 Electronic Sound Systems 69
Fig. 4-42 Basic Elements 70
Fig. 4-43 Microphones 71
Fig. 4-44 Electronic Control 71
Fig. 4-45 Loudspeakers 71
xi
Fig. 4-46 Loudspeaker Systems 72
Fig. 4-47 Central Loudspeaker Systems 73
Fig. 4-48 Distributed Loudspeaker System 73
Fig. 4-49 Seat-Integrated Loudspeaker System 74
Fig. 4-50 Column Loudspeaker System 74
Fig. 4-51 Electronic Background Masking Systems 75
Fig. 5-1 the Path of Microsoft Visual Basic 6.0 Package Tool 77
Fig. 5-2 Microsoft Visual Basic 6.0 Package Tool 77
Fig. 5-3 AATT installation files 78
Fig. 5-4 AATT installation program 1 79
Fig. 5-5 AATT installation program 2 80
Fig. 5-6 the position of AATT in computers 81
Fig. 5-7 the Interface Test 1 82
Fig. 5-8 the Interface Test 2 82
Fig. 5-9 Period Calculator 83
Fig. 5-10 Frequency Calculator 83
Fig. 5-11 Sound Intensity Calculator 84
Fig. 5-12 Sound Intensity Level Calculator 84
Fig. 5-13 Noise Reduction with Distance Calculator 85
xii
Fig. 5-14 Noise Reduction Calculator 85
Fig. 5-15 Initial Time Delay Calculator 86
Fig. 5-16 Reverberation Time Calculator 86
Fig. 5-17 Mass Law Calculator 87
Fig. 5-18 Noise Reduction Calculator 87
Fig. 5-19 Frequency Calculator 88
Fig. 5-20 Period Calculator 88
Fig. 5-21 Sound Intensity Calculator 89
Fig. 5-22 Sound Intensity Level Calculator 89
Fig. 5-23 Noise Reduction with Distance Calculator 90
Fig. 5-24 Noise Reduction Calculator 90
Fig. 5-25 Reverberation Time Calculator 91
Fig. 5-26 Mass Law Calculator 91
Fig. 5-27 Noise Reduction Calculator 92
Fig. 5-28 Sound examples in different frequencies 93
Fig. 5-29 Sound examples in different loudness 93
Fig. 5-30 Talk in different reverberation time 93
Fig. 5-31 A piece of music with and without reverberation 94
Fig. 5-32 Sound reflection video 94
xiii
Abstract
This research aims to create an architectural computer-supported acoustics teaching
tool AATT, which stands for Architectural Acoustics Teaching Tool. The AATT uses
widely accepted principles and uses known algorithms. The goal is the creation of a
digitalized tool that provides a more interactive way of learning architectural acoustics
knowledge, by visualizing and auralizing the theoretical knowledge into vivid
examples. The main innovative feature is that it integrates acoustics knowledge with
acoustical examples, animations, videos, interactive calculation function and graphics.
Most existing acoustical software tools, such as CATT-Acoustics and Ramsete, are
aimed at professionals who already have significant acoustics experience. The tools are
complicated to use and expensive to buy. Students need a free, easy to use teaching
program which can provide basic knowledge about architectural acoustics. The AATT
is written using Visual Basic. A tutorial is provided. Program debugging is also
presented.

1
Chapter 1. Introduction of the AATT
1.1 Introduction
This research presents a digitized program AATT which provides students a more
interactive way of learning architectural acoustics knowledge. The main innovative
feature is that it integrates the acoustics knowledge with acoustical examples,
animations, videos, interactive calculation function and graphics. (See figure 1-1 to
1-5)

Fig. 1-1 Animation of Initial Time Delay

Fig. 1-2 Calculation Function-Frequency Calculator

2

Fig. 1-3 Sound Example-Loudness

Fig. 1-4 Interactive Graphic-Reverberation Time

Fig. 1-5 Video of Sound Reflection
Produced by ARUP
3
The AATT is written using Visual Basic. 6.0. Visual Basic is a convenient programming
language for creating graphical interface design. By manipulating the control
components provided by Visual Basic itself, users can develop their own application.
“Programs written in Visual Basic can also use the Windows API, but doing so requires
external function declarations,” (Visual Basic) such as play MIDI, which can provide
sound.

1.2 Hypothesis
This acoustics teaching program intends to be user friendly. Rather than teaching by
using abstract theoretical formulae, this program incorporates visual and acoustical
examples for the beginners to instantly grab the intuition behind those complicated
equations. It will be available on the internet. It can calculate reverberation time, sound
absorption, sound transmission loss, and other acoustics parameters when initial
parameters are input by users. This program can also use the ray-diagram analysis
method to calculate the initial-time-delay gap in rooms which have sound-reflecting
ceilings when the sound source position and receiver position are given.

4
1.3 The Importance of the AATT
Students can study acoustics knowledge by reading books, however acoustics is a
science about sound, and it would be better to learn it combined with ‘hearing’.
Existing acoustical software programs, such as CATT-Acoustics and Ramsete, are
designed for professionals, who have had some experience already, and they are not
well suited for use by novices Therefore, the AATT provided in this paper presents
beginners an effective way to learn acoustics with vivid experiences.

Fig. 1-6 CATT-Acoustics Program
http://www.rpginc.com/products/catt/index.htm

This program is base on basic architectural acoustics knowledge primarily derived from
existing written sources. It covers main architectural acoustics knowledge, and it can be
updated easily by the author for future development. The updated AATT program can
5
be uploaded to a server and then users can download and update the program on their
computer promptly.

The existing acoustical software tools have the primary function of room acoustics
modeling, which can do simulations and design, but they are complicated to use and
expensive or only available inexpensively as a demo version. The AATT is for the
students who are learning acoustics, and it can be downloaded from internet for free.

1.4 Hypothesis Explanation/Elaboration: Terms
1.4.1 Sound Absorption
Absorption refers to the sound waves absorbed by a material. The absorption is the
reduced sound energy which is the difference between the total reflected and
transmitted sound energy, and the initial incident energy. It is the material’s property
“that changes acoustic energy into usually heat energy.” (Absorption (acoustics),
2009) A material or surface that absorbs sound waves does not reflect those waves. A
given material’s absorption ability depends on sound frequency and the shape,
mounting method, location, size. (Absorption (acoustics), 2009) Usually a given
material has a most “sensitive” sound frequency.

6
The absorption coefficient α expresses the sound absorption effectiveness of a material.
“This coefficient describes the fraction of the incident sound energy that a material
absorbs.” (Absorption (acoustics), 2009)

Theoretically, the coefficient α is between 0 (no sound energy absorbed) and 1.0 (all
sound energy absorbed).

The total sound absorption in a room can be expressed as:
a = S
1
α
1
+ S
2
α
2
+ .. + S
n
α
n
= ∑ S
i
α
i

Where
a = the absorption of the room (sabins)
S
n
= area of the actual surface (ft
2
)
α
n
= absorption coefficient of the actual surface

1.4.2 Reverberation Time
The reverberant sound in a room decreased with time as the sound energy is absorbed
by room surfaces and materials, such as ceiling, floor and walls. In a 'live' room, which
is more sound reflective, the sound will disappear comparatively in a longer time. In a
“dead” room, which is more sound absorbent, the sound will disappear comparatively
7
in a shorter time. But the time which the reverberations entirely absorbed depends on
the original sound level, and also depends on the sensitivity of the observer’s hearing.
In order to create a reproducible parameter, the definition of a standard reverberation
time was provided. It is the time for a sound to decrease by 60 decibels. The
reverberation time can be shaped to allow an approximate calculation. (Reverberation
Time) (As we know, the abbreviation RT60). Reverberation time is not for a single
frequency sound but is defined for wide band waves.

The Reverberation time depends on the total sound energy absorbed by the surface
materials in the room and the room volume. In an empty room, the reverberation time
is proportional to the ratio of volume to sound absorption. Sabine's reverberation
equation was developed in the late 1890s in an empirical fashion. (Reverberation Time)

Sabine established a relationship between the reverberation time, the room volume, and
its total absorption (in sabins). This is given by the equation:

8
RT60=0.05V/a
Where
RT60=reverberation time (s)
V=room volume (ft
3
)
a=total ft
2
of room absorption (sabins)

1.4.3 Transmission Loss
Transmission loss (TL) is a measure of how much sound energy is reduced in
transmission through materials. (Egan, 2007) The unit is one decibel. The more
massive a material, the higher is its TL.

Transmission loss can be expressed as follows:
TL=10 log1/τ
Where
TL=sound transmission loss (dB)
τ=sound transmission coefficient (no units)

9
1.4.4 Other Important Terms
Sound absorption, reverberation time and transmission loss are introduced above.
Sound level, echoes, ray-diagram, initial time delay and STC are almost as important.

1.5 Hypothesis Explanation/Elaboration: Study Boundaries
1. The domain of this study includes basic acoustics theory, sound absorption, room
acoustics, sound isolation and electronic sound system. These contents are the basic
knowledge of architectural acoustics, which are the necessary parts for learning
acoustics. The domain of this study also includes software programming using Visual
Basic, which is the tool to make this program.

2. This study does not include mechanical system noise and vibrations. These two parts
are for engineers who want to do acoustics design for mechanical systems. So, in this
thesis, they are not included.

1.6 Hypothesis Explanation/Elaboration: Scope of Work
1. In this study, the AATT program will be finished via Visual Basic.
2. Some tests and independent evaluation of the AATT program will be provided.
3. A tutorial of the AATT program will be delivered.
10
1.7 Chapter Structure for what is coming next
1. Chapter 2 includes the Literature and background study, including the introduction of
existing acoustics software tools.

2. Chapter 3 presents the program’s contents, structure, and the tool for writing the
program. This program can be visualized as a tree structure. It contains five basic parts,
which are Basic Theory, Sound Absorption, Room Acoustics, Sound Isolation, and
Electronic Sound Systems. Each part includes detailed branches. (See figure 1-7)

Fig. 1-7 Program Structure

11
3. Chapter 4 is the tutorial of the Architectural Acoustics Teaching Program

4. Chapter 5 is the program debugging. The debugging includes two types. The first
part debugging is performed according to some tests which were finished by the author,
including program installation test, basic error test, calculators test and sound examples
test. (See figure 1-8) The second part debugging was finished according to some
experience and comments which provided by four students after using this program.

Fig. 1-8 Error Checking

5. Chapter 6 includes the conclusions of this thesis and future work on AATT
development.
12
Chapter 2. Introduction of Architectural Acoustics and Acoustics
Software Tools
2.1 Introduction to architectural acoustics
Architectural acoustics is the science of sound performance within buildings. “The first
application of architectural acoustics was in the design of opera houses and then
concert halls.” (Architectural acoustics, 2009) Among them, La Grande Salle
(Montreal Canada, 1963), and the Music Pavilion (Los Angeles, 1965) are widely
acclaimed due to their outstanding acoustical quality. Architectural acoustics not only
includes the design for music places such as broadcast studios, concert halls, home
theaters, and listening rooms for media playback, but also includes speech privacy,
noise reduction, sound isolation and other aspects about sound within buildings. Mainly,
there are four science categories have been generated from architectural acoustics:

(1) Building skin envelope: Analyze noise transmissions between building exterior
envelope and the interior roofs, walls, eaves, windows, doors, and penetrations are the
major noise paths. Effective controls and skin designs could guarantee space
functionality, in which an architect need to consider over sustainability objectives,
unique local conditions, geometric complexities, and budget constraints. An example
13
would be a suitable home design given it is located close to a noisy road, or near an
airport.

(2) Inter-space noise control: Limit and control noise transmissions between rooms.

The typical sound paths between rooms are partitions, ceilings, interior walls, doors,
HVAC ducts, windows and other penetrations. An example would be a common wall
design in an apartment complex to minimize the sound influences of adjacent neighbors
to guarantee space functionality as well as speech privacy.

(3) Interior space acoustics: Design room's surfaces according to sound absorbability
and reflecting properties.

Follows the idea that too much reverberation time in a room can result in a poor speech
intelligibility.

(4) Mechanical equipment noise: aim to reduce noise generated by buildings’ interior
mechanical systems, such as air handling units, pumps, elevators, and generators.

14
The paucity or lack of knowledge in acoustics among architects and architectural
students could lead to severe acoustical problems in buildings at the design stage.
Famous examples are London’s Royal Festival Hall (1951) and New York’s
Philharmonic Hall (1962). They were mainly criticized for their acoustical deficiencies.

Moy, Jorge argued in his paper that “this paucity of knowledge on the part of the
architects may be attributed to the lack of emphasis on the role of acoustics in most
architectural curricula in Peruvian universities.” (Moy, 2002)

The US has a long history in architectural acoustics education and research since early
1900’s with the founder of scientific architectural acoustics Wallace Clement Sabine in
Harvard University. Later his contribution has been widely spread in universities
including MIT, UCLA and Brown University as well as industrial and consultants’
laboratories. Due to the lack of research funds, however, many of the experimental
studies as well as new field knowledge are performed and developed in industrial
laboratories, which are mainly sponsored by funds with commercial aims, while
significant advances are being made by most European countries (like Germany and
Holland), as well as Canada and Australia due to adequate government support for
research and education in universities. Among those greatest achievements, the 4 years
15
ago inaugurated electroacoustic system in the Kremlin Palace could provide adjustable
and relatively good acoustics to 6000 people by generating artificial reverberation.
Regrettably, less government support has been issued to architectural acoustics. Some
universities, however, offer courses on acoustics science like in UCLA and in
Rennselaer Polytechnic Institute. As Jaffe, J. Christopher has mentioned in his paper
that there were 14 units certificate undergraduate courses which were entitled Sonics in
Architecture from fall 1997. After that, an extension was made to include the program
in the Master of Building Science degree. (Jaffe, 2003) Leo Beranek, who is from MIT,
is a pioneer in the acoustics of concert halls and noise control research. He has
published twelve books on these topics, such as Riding the Waves (March 2008). He
has received many awards including “the Presidential National Medal of Science,
presented in 2003.” ( Leo Beranek, 2009)

Recently, digital simulation, computer-oriented measurement techniques and Monte
Carlo simulation in acoustic performance of architectural spaces have come to play an
important role in architectural education. Unfortunately however, students in an
architecture major often hesitate to use complicated theoretical formulae and models
which are commonly applied by physicists and acousticians.

16
One way to solve this problem is to “develop simple calculation simulation tools to
help architectural students to understand basic acoustic principles.” (Kang, 2008)

Five tools could be developed according to his paper, with the focus on effective key
parameters and on how to present teaching materials scientifically and visually:

(1) sound distribution behind an environmental noise barrier, with parameters
including barrier height, source-barrier distance, and source height; (2) sound
distribution in a rectangular street canyon, with parameters including street length,
width, building height, boundary absorption coefficient, air absorption, and the
height of receiver plane; (3) reverberation time calculation in a rectangular space,
with parameters including room dimensions and boundary absorption coefficients,
where a database of absorption coefficients is also included; (4) absorption of
perforated panel absorbers, especially micro-perforated panel absorbers, with
parameters including hole size, hole spacing, panel thickness, and depth of airspace;
(5) digital audio animation for urban soundscape design, considering idealized
cross-streets and squares in a 2D environment, where the sound file with multiple
sources can be played back, with reverberation effects. (Kang, 2008)

The biggest problem for the means mentioned above, for an architecture student, is that
it might require too long and too tough a period to get familiar with and able to apply
the acoustics knowledge, since even for a science major, to learn acoustics requires
prepared knowledge from physics and calculation techniques in mathematics.
Therefore, two issues need to be settled down:

17
What content from acoustics should be taught to architecture students?
How to teach those materials in a most effective way?

To answer the first question, many works have been done by many professors,
professionals, and educators. The typical content is architectural acoustics course is of
seven parts: “basic sound and vibration theory, sound absorption, room acoustics,
sound isolation, mechanical system noise and vibrations, speech privacy, and electronic
sound system” (Egan, 2007)

This research is addressed to answer the second question and to present an effective
teaching tool described below. The “spirit” of this tool is to simplify and vivified
complicated theories by visualizing and auralization the acoustic phenomenon to
intuitional understanding, followed by practical self-performed examples to deepen
comprehension and the same time to master necessary means of acoustic calculating,
while providing basic acoustics knowledge, explanations, and commonly accepted
formula as assistance.

18
2.2 Existing Acoustics Software Tools
There are over 30 acoustics software tools that can perform acoustics analysis and
design, noise and vibration prediction, high quality audio design, room acoustics
modeling, and other acoustics work. The following several paragraphs describe some of
the most important existing software tools, including their advantages and
disadvantages.
2.2.1 A brief description of EASE
EASE stands for Electro Acoustic Simulators for Engineers. It was developed by some
German acoustical engineers approximately 15 years ago. It is an acoustical analysis
software tool that can be used for designs, such as to determine the best location of
speakers or to figure out the best position to put acoustical materials in a room. EASE’s
main function includes:

Simulation of the reverberation time and Clarity of seven different frequency of
electronic sound between 125Hz and 8000Hz, direct sound field distribution and
reverberation distribution, consonant loss ratio, speech intelligibility, and ray
diagram analysis. (Enhanced Acoustic Simulator for Engineers - E.A.S.E.
Software, 2008)

This tool is not suitable for teaching architecture students who are the beginners, since
firstly, this tool emphasizes only on the loudspeaker systems design in a room not on
19
knowledge of overall architectural acoustics; secondly, rather than an acoustics
teaching program for students, it is designed for users who have already achieved
certain level of acoustics design experience and could apply their techniques without
needing the primary instructions of the basic formulas.

Fig. 2-1 EASE Program
http://img11.nnm.ru/imagez/gallery/7/e/b/2/c/7eb2c2fc953a238356d2fd1ff0e7f77c.jpg

2.2.2 A brief description of NEMPEE Acoustics Software
NEMPEE Acoustics Software is a software tool for acoustics engineers and architects.
It could perform mathematical calculations for users to get the room’s acoustical
parameters, such like the reverberation time. (NEMPEE Acoustics software, 2009)
20
This tool is not suitable either, however, for teaching architecture students, similarly
because this tool is more applied by professionals rather than beginners to perform
acoustics simulation, which does not give the integrated architectural acoustics
knowledge. Rather, it assumes that users already got the necessary basic acoustics
knowledge. For example, users need to know what the reverberation time is, before
simulating reverberation time.

Fig. 2-2 EASE Program
http://www.nempee.com/AcouSoft.htm

For the reverberation time design, users need to select the application type; input the
room volume, humidity, wall surfaces area, and select absorption materials from its
database or edit more materials by the users themselves. This software can show the
users resulting reverberation figures and curves continuously to compare with the
desired reverberation time. (NEMPEE Acoustics software, 2009)
21

Fig. 2-3 EASE Program
http://www.nempee.com/AcouSoft.htm

NEMPEE Acoustics Software will also generate a detailed report including materials
applied on various surfaces with their area and absorption coefficients. (NEMPEE
Acoustics software, 2009)

2.2.3 A brief description of CATT-Acoustics
CATT-Acoustic was developed in Goeteborg (Sweden) by Bengt-Inge Dalenbaeck. It is
a comprehensive software room acoustics modeling tool, which can do prediction in
high fidelity. It can do the simulation of a room with variable sound sources as well as
surfaces. Based on its specific algorithm, it can accurately predict the acoustic
performance of a space before built, and provide fairly realistic auralization. This
22
means the designers can select the best possible acoustic treatment for the purpose and
budget. (CATT-acoustic-modeling, 2009) (CATT Acoustics, 2009) CATT-Acoustic
suits the requirements of professional designers, based on their acoustics knowledge
and experience, whereas it cannot easily be used as a teaching tool for the student
beginners who are leaning acoustics, due to the lack of explanations of the very basic
conceptions.

Fig. 2-4 CATT-Acoustic Program
http://www.rpginc.com/products/catt/index.htm

2.2.4 Other Acoustics Tools
In addition to the tools introduced above, there are many other tools that have the same
functions, but also have the same problem, in the sense of they are designed for
professionals but not for beginners.
23
Below is a list of acoustics software tools that are found on internet. (Acoustical
Software, 2009)

ESI Group's AutoSEA2 - Noise and Vibration Prediction Based on SEA
EnviroMeasure's AVAAZ Inovations, Inc. - Software Products for Clinical,
Research, and Industrial Applications Involving Speech and Spoken Language
EnviroMeasure's Online Acoustics Software Tools and Demos
Virginia PolyTechnic Istitute and State University, Vibration and Acoustics
Laboratories Active Noise Control Experiment Shareware
ADEM acoustic analysis and design software for engine mufflers and flow ducts
AcuVib acoustic and vibration engineering toolbox
AURORA auralization software
Integrated Sound Software BEM (Boundary Element Method) software for
acoustics
CATT-Acoustic room acoustics prediction and auralization software
Collins & Aikman's COMET Boundary Element Software For Noise and Vibration
Prediction
Syntrillium CoolEditPro/CoolEdit2000 digital audio software package
Brüel Bertrand Johnson Acoustics CORTI Health Conservation Program (HCP)
management software
Structural Research and Analysis Corporation COSMOS design analysis software
DSPCon digital signal processing and data acquisition tools
Echocsan acoustics engineering software
FIReverb Suite FIR generator and multi-channel reverb/mix convolver software
Fletcher and Galt's Articulation Index software (freeware)
GFu-Kwun Hwang's Fourier Synthesis, National Taiwan Normal University
FreeSEA statistical energy analysis freeware
Brüel Bertrand Johnson Acoustics HPD Select hearing protection device selection
software
ESI Group's I-DEAS Vibro-Acoustics - Comprehensive Software for Solving
Vibro-Acoustic Problems
Institut of Wiener Klangstil Musical Acoustics Software
Ptolemy Services Jade 2 environmental noise monitoring software
Wave Imaging K-Space acoustics software for biomedical imagaing and
underwater acoustics
24
Lake DSP acoustic analysis tools
LISA finite element software
LMS International
MacNeal-Schwendler Corporation MSC/NASTRAN for Noise, Vibration, and
Harshness (NVH) problems
The Mathworks science and engineering software
NEMPEE audio acoustics and software
Office of Naval Research Ocean Acoustics Library
QSound Labs QCreator 3D audio software
Ramsete room acoustics modeling
Cambridge Collaborative, Inc. SEAM acoustic and vibration prediction software
Scientific and Technical Software SK-A VaM low cost data acquisition
Peter Meijer'sSound synthesis software page
Sound Waves educational software program
Cetacean Research Technology Spectra Series spectral analysis software for
bioacoustics and underwater acoustics
Visualization Software LLC Spectrogram audio spectrum analysis
Test Tone Generator
Noldus Information Technology Ultravox for automatic monitoring of ultrasonic
vocalizations
Vibro-Acoustics V-A Select HV AC silencer selection software
Neutrik Cortex Instruments VIPER visual perception of auditory signals software
Scientific and Technical Software VNoise vibroacoustic tool for noise radiation
problems
Vibrationdata.com acoustics, shock, and vibration software
Vibro-Acoustic Sciences acoustic and vibration software
VibroTek Vibration Technologies noise and vibration analysis
AETC Wideband Acoustic Signal Processing (WASP) sonar system software
Morset Sound Development WinFLAG - software for estimating the acoustic
performance of constructions
Morset Sound Developm ent WinMLS - software for high quality audio, acoustics,
and vibrational measurements (Acoustical Software, 2009)
25
Chapter 3. AATT programming
The configuration of the AATT can be visualized as a tree structure. It contains five
basic parts, which are Basic Theory, Sound Absorption, Room Acoustics, Sound
Isolation, and Electronic Sound Systems. Each part includes detailed branches. These
five parts are the basic contents for learning architectural acoustics. (See figure 3-1)

Fig. 3-1 Program Structure

3.1 The main book used for making the program
The main book used to create this Architectural Acoustics Teaching Software is
“Architectural Acoustics” written by M. David Egan. This book has seven chapters
26
which are Basic Theory, Sound Absorption, Room Acoustics, Sound Isolation,
Mechanical System Noise and Vibration, Speech Privacy, and Electronic Sound
Systems. It gives basic concepts, practical computation and design methods of
architectural acoustics.

The most basic and important contents in some of chapters are selected in making this
Architectural Acoustics Teaching Software. This software does not contain the
mechanical system noise and vibrations, nor speech privacy.

3.2 The tool for writing the program
This architectural acoustics software was written via Visual Basic 6.0. (See figure 3-2)
“Visual Basic (VB) is a third-generation event-driven programming language and
integrated development environment (IDE) from Microsoft for its COM programming
model.” (Visual Basic, 2009)

VB has graphical development, it is considered a relatively easy to learn and use
programming language.
27

Fig. 3-2 Visual Basic Interface

Visual Basic was derived from BASIC and enables the rapid application
development (RAD) of graphical user interface (GUI) applications, access to
databases using Data Access Objects DAO, Remote Data Objects RDO, or
ActiveX Data Objects ADO, and creation of ActiveX controls and objects.
Scripting languages such as VBA and VBScript are syntactically similar to Visual
Basic, but perform differently. (Visual Basic, 2009)

Users can develop their application using the control components which are provided
with Visual Basic itself. “Programs written in Visual Basic can also use the Windows
API, but doing so requires external function declarations,” (Visual Basic, 2009) such
as play MIDI.

28
3.3 The structure of Architectural Acoustics Teaching Program
At the beginning, this program shows the friendly interface. It will ask the user’s name,
and ask the users whether they have used this program before. If yes, this program will
show the main menu directly, if not this program will show the introduction of how to
use this program first. (See figure 3-3 and 3-4)

Fig. 3-3 AATT Interface

Fig. 3-4 AATT Greeting Interface

This program uses tree structure. It contains five basic parts, which are Basic Theory,
Sound Absorption, Room Acoustics, Sound Isolation, and Electronic Sound Systems.
(See figure 3-5)
29

Fig. 3-5 AATT Main Menu

3.3.1 Basic Theory
The Basic Theory includes five detailed parts, which are Frequency, Period and Wave
Length, Sound Intensity, Sound Intensity Level, Loudness, Noise Reduction, and
Decibel Addition. (See figure 3-6)
30

Fig. 3-6 Basic Theory Interface

In each part, it contains the basic knowledge and introduction, and some calculations,
such as period, frequency, sound intensity, noise reduction and decibel addition. It also
contains some animations and sound examples. (See figure 3-7 and 3-8)

Fig. 3-7 Period Calculator
31

Fig. 3-8 Sound Frequency Interface
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

In Frequency, Period and Wave Length part, this program includes the sound example
in different frequency. The user can select 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1000 Hz,
2000 Hz, and 4000 Hz, to have a direct feeling of sound in different frequencies. The
users can also compare sound in different loudness in Loudness part. The sound comes
from the computer’s speakers. (See figure 3-9 and 3-10)

32

Fig. 3-9 Sound Example in Different Frequency

Fig. 3-10 Sound Example in Different Loudness

3.3.2 Sound Absorption
The sound absorption contains three parts: sound absorption coefficient, noise
reduction coefficient, and room noise reduction with treatment. It has a calculator for
noise reduction with treatment. (See figure 3-11)
33

Fig. 3-11 Sound Absorption Interface

3.3.3 Room Acoustics
The room acoustics includes three parts, which are sound reflection, diffusion and
diffraction, Initial time delay, and Reverberation time. (See figure 3-12)

34

Fig. 3-12 Room Acoustics Interface

In the room acoustics portion, it shows the knowledge mainly via animations, which
can give the users a vivid graphic feeling of sound reflection, diffusion, diffraction and
initial time delay. (See figure 3-13)

Fig. 3-13 Animations of Sound Reflection, Diffusion, and Diffraction

35
For sound reflection, this program also contains a piece of video to show the sound
reflection trace in an onion shape space. This video was produced by ARUP. (See
figure 3-14)

Fig. 3-14 Video of Sound Reflection
Produced by ARUP

The other main function is the reverberation time calculator. Users can enter the room
dimension, and select materials for the room surfaces, such as walls, floor, and ceiling
from the database. The database has 18 different materials for the wall, 9 different
materials for the floor, and 15 different materials for the ceiling. (See figure 3-15)

36

Fig. 3-15 Reverberation Time Calculator

After the user enters the parameters. The program can give users the reverberation time
for the room they designed. It also will give a graphic that shows what kind of room
this reverberation time fits. (See figure 3-16)

Fig. 3-16 Interactive Graphics for Reverberation Time
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing

37
3.3.4 Sound Isolation
In this part, this program will show the users Transmission Loss and STC, Mass Law,
and Noise Reduction between Rooms. (See figure 3-17)

Fig. 3-17 Sound Isolation Interface

3.3.5 Electronic Sound Systems
In this section, this program will show users the Electronic Sound Systems, including
Basic Elements, Loudspeaker Systems, and Electronic Background Masking Systems.
(See figure 3-18)

38

Fig. 3-18 Electronic Sound Systems Interface
39
Chapter 4. AATT Program Tutorial
4.1 Interface
At the beginning, the AATT shows a friendly interface. It asks users to enter their
names first, and then click “Enter” button. (See Figure 4-1)

Fig. 4-1 Program Interface
http://www.bjswly.com/gjdjy/gjdjyss002.asp

After the first interface the users can select to go to the Main Menu directly if they have
used this program before and do not want to see the instructions again, or to see the
instructions if this is the first time they use this tool and want to get a general idea of
what this program will do. (See Figure 4-2)

40

Fig. 4-2 Second Interface

If the user selects “Yes, go to the Main Menu,” this program will go to the “Main
Menu” page. It shows the five parts “Basic Theory,” “Sound Absorption,” “Room
Acoustics,” “Sound Isolation,” and “Electronic Sound Systems”. The users can click
the buttons to select any area they want to study. Or they can click the “Back to the
Introduction” to see the software introduction again. (See Figure 4-3)

41

Fig. 4-3 Main Menu

If the user selects “No, I want to see the introduction”, this tool will go to the
“Introduction” page. Users can get a general idea of what this program can do. And in
which areas the AATT is better than a book. After the instruction, users can go to the
Main Menu page by clicking the “Main Menu” button. (See Figure 4-4)

42

Fig. 4-4 Program Instructions
http://hi.baidu.com/momo1st/album/item/ea7599f7878e6c3f730eec35.html
http://www.phoenixnv.com/images/slidshow/Acoustics1.jpg

4.2 Basic Theory
In the Basic Theory section, the architectural teaching tool will show users the basic
theories of acoustics, including “Frequency, Period and Wave length,” “Sound
Intensity,” “Sound Intensity Level, Loudness,” “Noise Reduction,” and “Decibel
Addition”. (See Figure 4-5)
43

Fig. 4-5 Basic Theory

4.2.1 Frequency, period and Wave length
This content is contained in two pages. On the first page it shows the definition of
sound wave and how the sound wave transfers in the air. (See Figure 4-6)

44

Fig. 4-6 Sound Frequency
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing
http://www.chinajxgcs.cn/solidworks/image2/30-28-1.gif.

On the second page it gives the definition of frequency, period, and the wave length.
On this page it also contains the sound examples, and calculation function. (See Figure
4-7)

45

Fig. 4-7 Sound Frequency 2
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.
http://www.divediscover.whoi.edu/expedition12/hottopics/images/sound1-en.jpg

When users click “Hear sounds in different frequencies!” a window will be open. Users
can select the sound frequency and click “Beep” to get a real feeling of sounds in
different frequencies. (See Figure 4-8)
46

Fig. 4-8 Sound Examples in Different Frequencies

Users can also click the “Want to calculate frequency or period?” button to use the
calculation function. They can select “I know Frequency f” to calculate the Period T or
“I know Period T” to calculate the Frequency f. (See Figure 4-9)

47

Fig. 4-9 Period and Frequency Calculators

4.2.2 Sound Intensity
This content contains two pages. The first page gives the definition of sound intensity,
and contains a calculator for sound intensity. (See Figure 4-10 and 4-11)

48

Fig. 4-10 Sound Intensity Introduction
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

Fig. 4-11 Sound Intensity Calculator

After the user clicks the “Continue” button, the second page uses an animation to
describe the inverse-square law. By clicking the “How” button beside the
inverse-square law formula, the user can see the explanation of where this formula
comes from. (See Figure 4-12 and 4-13)
49

Fig. 4-12 Inverse Square Law Introduction
http://www.skolor.nacka.se/samskolan/eaae/summerschools/Hubble.html

Fig. 4-13 Inverse Square Law
Explanation, M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross
Publishing.

4.2.3 Sound Intensity Level
This content includes the definition of sound intensity level, a decibel scale showing
the intensity level of some familiar sounds, and a sound intensity calculator. (See
Figure 4-14)
50

Fig. 4-14 Sound Intensity Level Introduction
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.
http://www.colorado.edu/physics/phys1240/phys1240_fa05/handouts/decibel%20examples.jpg

4.2.4 Loudness
This content includes the definition of loudness, the unit phon and sone. It also has an
equal-loudness contours chart. By clicking the button “Listen to a sound in different
loudnesses,” users can open a window, and choose a different loudness from “1 x
Unit,” “2 x Unit,” and “4 x Unit” to hear a doorbell sound. (See Figure 4-15 and 4-16)
51

Fig. 4-15 Loudness Introduction,
http://hyperphysics.phy-astr.gsu.edu/Hbase/sound/loud.html
http://www.indiana.edu/%7Eemusic/etext/acoustics/chapter1_loudness.shtml

Fig. 4-16 Sound Examples in Different Loudness

4.2.5 Noise Reduction
This content includes the explanation and a chart to show how the noise reduces with
distance. It also has a calculator which the users can calculate the noise reduction. (See
Figure 4-17)
52

Fig. 4-17 Noise Reduction Introduction
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

4.2.6 Decibel Addition
In this section, the AATT shows how to calculate sound intensity level if there is more
than one sound source. The user can click “Prefer a simplified calculation?” button to
get a table to combine sound intensity level rapidly. (See Figure 4-18)

53

Fig. 4-18 DeciBel Addition
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

4.3 Sound Absorption
In the Sound Absorption part, the AATT will show the users the sound absorption
knowledge, including Sound Absorption Coefficient, Noise Reduction Coefficient, and
Room Noise Reduction with Treatment. (See Figure 4-19)
54

Fig. 4-19 Sound Absorption
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

4.3.1 Sound Absorption Coefficient
In this page, the definition of sound absorption coefficient and the total room
absorption are given. (See Figure 4-20)

Fig. 4-20 Sound Absorption Coefficient Introduction
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.
55
4.3.2 Noise Reduction Coefficient
In this section, the definition of noise reduction coefficient (NRC) and the relationship
to sound absorption coefficient are given. (See Figure 4-21)

Fig. 4-21 Noise Reduction Coefficient Introduction
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

4.3.3 Room Noise Reduction with Treatment
In this section, this program shows how sound-absorbing material is effective in
controlling noise buildup within a room. (See Figure 4-22)
56

Fig. 4-22 Room Noise Reduction with Treatment
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

It also has a noise reduction calculator. Users can input the walls, ceiling and floor’s
area and sound absorption coefficient of “before treatment” and “after treatment” to get
the noise reduction result. (See Figure 4-23)

57

Fig. 4-23 Room Noise Reduction with Treatment Calculator

4.4 Room Acoustics
In this section, the AATT shows the basic knowledge of room acoustics, including
sound reflection, diffusion and diffraction, initial time delay, and reverberation time.
(See Figure 4-24)

Fig. 4-24 Room Acoustics
58
4.4.1 Sound Reflection, Diffusion and Diffraction
There are three pages in this section, each for sound reflection, sound diffusion, and
sound diffraction. It gives the definition, and provides some animations to present the
content. (See Figure 4-25)

Fig. 4-25 Sound Reflection, Diffusion and Diffractio
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

Users can click the button “Click here to see how sound reflection works in an
onion-shape bottle” to see a piece of video which produced by Arup. (See Figure 4-26)

59

Fig. 4-26 Sound Reflection Video
Produced by ARUP

4.4.2 Initial Time Delay
In this section, it includes two pages. The first page uses the animation to show the
principle of initial time delay. (See Figure 4-27)

60

Fig. 4-27 Initial Time Delay
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

The second page describes the ray-diagram analysis which is the method to calculate
the initial time delay. It also contains an initial time delay calculator. Users can input
the horizontal distance between the sound source and the receiver, sound source height,
receiver height, horizontal distance between the sound source and the reflecting surface,
and reflecting surface height, to get the initial time delay gap. (See Figure 4-28 and
4-29)
61

Fig. 4-28 Ray Diagram
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

Fig. 4-29 Initial Time Delay Gap Calculator
62
4.4.3 Reverberation Time
In this section, the definition and description of reverberation time are given. The users
can click the “Reverberation Time Calculation” button to use the calculation function.
Users also can click the “Hear sounds in different reverberation time!” to hear two
pieces of sound files, including a piece of talk and a piece of music. (See Figure 4-30)

Fig. 4-30 Reverberation Time,
http://hyperphysics.phy-astr.gsu.edu/hbase/Acoustic/reverb.html

In the reverberation time calculator, users need to enter the room dimension first, and
then select material of walls, floor, and ceiling from the database. After the “Calculate”
button is clicked, this program will give a graphic that show what kind of room the
result fits. (See Figure 4-31 and 4-32)

63

Fig. 4-31 Reverberation Time Calculator

Fig. 4-32 Reverberation Time Result Graphic
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

After the user clicks the “Hear sounds in different reverberation time!” a window will
be opened. Users can select which sound file they want to hear. (See Figure 4-33)
64

Fig. 4-33 Sound Examples in Different Reverberation Time

In the “Talk” file, users will hear a piece of talk in 0 second, 1 second, 3 seconds, and 6
seconds reverberation time. (See Figure 4-34)

Fig. 4-34 Sound Examples- Talk

In the “Mozart” file, users will hear a piece of music with and without reverberation.
(See Figure 4-35)

65

Fig. 4-35 Sound Examples- Music
4.5 Sound Isolation
In this section, the AATT will show the users the knowledge of sound isolation,
including transmission loss and STC, mass law, and noise reduction between rooms.
(See Figure 4-36)

Fig. 4-36 Sound Isolation

66
4.5.1 Transmission Loss and STC
In this section, the definitions of transmission loss (TL) and STC are introduced. The
formulas of transmission loss for single material and composite material are given. (See
Figure 4-37)

Fig. 4-37 Transmission Loss and STC
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.
http://www.soundproofingcompany.com/media/library/understanding_stc/tranmission_loss_diagra
m.jpg

4.5.2 Mass Law
In this section, the mass law is introduced. It also provides a calculator according to the
mass law. (See Figure 4-38)

67

Fig. 4-38 Mass Law
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

4.5.3 Noise Reduction between Rooms
In this section, three basic factors affect the noise reduction between rooms are given.
The formula of the relationship between the three factors and noise reduction is also
introduced. (See Figure 4-39)

68

Fig. 4-39 Noise Reduction between Rooms
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

This section includes a calculator for the noise reduction between rooms. The user can
input the transmission loss of the common wall, absorption in the receiving room, and
the area of the wall transmitting sound, to get the noise reduction between two rooms.
(See Figure 4-40)

69

Fig. 4-40 Noise Reduction Calculator

4.6 Electronic Sound Systems
In the Electronic Sound Systems part, this program will show users the Electronic
Sound Systems knowledge, including Basic Elements, Loudspeaker Systems, and
Electronic Background Masking Systems. (See Figure 4-41)

Fig. 4-41 Electronic Sound Systems

70
4.6.1 Basic Elements
In this section, three basic elements of a sound-reinforcing system are introduced,
which are microphones, electronic controls, and loudspeakers. Users can click the
buttons below each representing picture to get more detailed information of each
element. (See Figure 4-42 to 4-45)

Fig. 4-42 Basic Elements
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.
http://www.elderly.com/also/new_instruments/items/PG58.htm
http://www.av010.com/cpzs/search.asp?page=3&sortid=1&typeid=4&cpsb=A
http://www.washingtonmusic.com/productimages/proaudio/specials/4326p.jpg

71

Fig. 4-43 Microphones
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.
http://img3.musiciansfriend.com/dbase/pics/products/6/5/5/539655.jpg
http://www.wesdooley.com/images/R84_fullsize_Lt.jpg
http://www.musicmarketing.ca/images/sontronics/st2cond_main.jpg

Fig. 4-44 Electronic Control
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.
http://www.combak.net/reimyo/CAT777600.jpg

Fig. 4-45 Loudspeakers
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing
http://nexus404.com/Blog/2008/05/01/dynaudio-announce-new-excite-hi-end-x-series-loudspeakers
-excite-x12-x16-x22-x32-x36/.
72
4.6.2 Loudspeaker Systems
In this section, four types of loudspeaker systems are introduced, which are central
loudspeaker system, distributed loudspeaker system, seat-integrated loudspeaker
system, and column loudspeaker system. Users can click each button to get more
detailed information of these four types of loudspeaker systems. (See Figure 4-46 to
4-50)

Fig. 4-46 Loudspeaker Systems
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

73

Fig. 4-47 Central Loudspeaker Systems
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

Fig. 4-48 Distributed Loudspeaker System
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

74

Fig. 4-49 Seat-Integrated Loudspeaker System
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

Fig. 4-50 Column Loudspeaker System
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

75
4.6.3 Electronic Background Masking Systems
In this section, the knowledge of electronic background masking systems is introduced.
The formula of loudspeaker spacing of electronic background masking systems is also
provided. (See Figure 4-51)

Fig. 4-51 Electronic Background Masking Systems
M. David Egan. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.

4.6.4 Summary
Chapter 4 presented the tutorial of the final version of the AATT. It showed users the
content of this program, and the instructions of how to use this program. The next
chapter will present the “debugging” for the first draft version of this tool. It will
include the debugging method, result and corrections
76
Chapter 5. AATT Program Debugging
5.1 Introduction of the debugging Method
This chapter will present the “debugging” for the AATT. The debugging is for the first
finished draft of AATT. The tutorial of this program in chapter 4 is for the final version,
which has been corrected and improved after debugging. The debugging is contained in
two parts. The first part of the debugging tests the program installation, some basic
error tests, such as calculators’ tests and sound examples’ test, which were performed
by the author. The second part of the debugging gathers user experiences and
comments which are provided by four students after using this program.

5.2 First Part of the Debugging
5.2.1 AATT package
The AATT is written in Visual Basic 6.0. In order to make it available to be used on
other computers, it should be packaged. The AATT is packaged by using the Package &
Deployment function in the Microsoft Visual Basic 6.0 Chinese Version. (See Figure
5-1 and 5-2)

77

Fig. 5-1 the Path of Microsoft Visual Basic 6.0 Package Tool

Fig. 5-2 Microsoft Visual Basic 6.0 Package Tool

After the package is finished, a folder will be generated. It includes a Support folder, an
Architectural Acoustics Teaching Tool.rar, a SETUP.LST, and a setup.exe file for the
AATT. (See Figure 5-3) This folder can be copied to any computer to install this
program as follows.

78

Fig. 5-3 AATT installation files

5.2.2 AATT installation
To install the AATT, the user should click the setup.exe first, and then the AATT
installation program will be started. (See Figure 5-4)

79

Fig. 5-4 AATT installation program 1

After “OK” is clicked, the program will let users select the folder in which they want to
install the program files. (See Figure 5-5) Then users can follow the instructions to
finish the installation.
80

Fig. 5-5 AATT installation program 2

After the installation is finished, users can click Start\All programs, and then will see
the AATT. Users can click it to open the AATT program. (See Figure 5-6)

81

Fig. 5-6 the position of AATT in computers

5.2.3 Navigation Test
This test is to check if all buttons are working properly, such as “Back” and “Continue”.
After the test, the result showed that the whole navigation can work correctly.

5.2.4 Input Test
The input test is to check if this program works when the user types some irregular
keys.

82
5.2.4.1 The Interface Test
Some irregular symbols are input, which are “!@#%*(1410>?” to test the greetings on
the second interface. The test result showed that the AATT can work well with this
input. (See Figure 5-7 and 5-8)

Fig. 5-7 the Interface Test 1

Fig. 5-8 the Interface Test 2

5.2.4.2 The Calculators Test
All the calculators in this program are limited to input numbers and decimal. It would
not accept any other keys. It also would not take more than one decimal for one input
83
box. For example, it would not take “000.123.023.023.” The test has proved that this
function is working properly. (See Figure 5-9 to 5-18)

Fig. 5-9 Period Calculator

Fig. 5-10 Frequency Calculator

84

Fig. 5-11 Sound Intensity Calculator

Fig. 5-12 Sound Intensity Level Calculator

85

Fig. 5-13 Noise Reduction with Distance Calculator

Fig. 5-14 Noise Reduction Calculator

86

Fig. 5-15 Initial Time Delay Calculator

Fig. 5-16 Reverberation Time Calculator

87

Fig. 5-17 Mass Law Calculator

Fig. 5-18 Noise Reduction Calculator

When calculators do not have input or have some unreasonable input, such as out of the
parameter’s range, this program will run an error check, and remind users what the
error is. The test showed that the error check function works properly. (See Figure 5-19
to 5-27)
88

Fig. 5-19 Frequency Calculator

Fig. 5-20 Period Calculator
89

Fig. 5-21 Sound Intensity Calculator

Fig. 5-22 Sound Intensity Level Calculator
90

Fig. 5-23 Noise Reduction with Distance Calculator

Fig. 5-24 Noise Reduction Calculator
91

Fig. 5-25 Reverberation Time Calculator

Fig. 5-26 Mass Law Calculator
92

Fig. 5-27 Noise Reduction Calculator

The Sound and Video Examples Test
This test is to check if all the sound and video examples work properly. The sound
examples include sounds in different frequencies, sounds in different loudness, a piece
of talk with 0 second, 1 second, 3 seconds and 6 seconds reverberation, and a piece of
music with and without reverberation. The video example is an animation of sound
reflection (Produced by Arup). The test result showed that all the sounds and video
work properly on the author’s computer. (See Figure 5-28 to 5-32)
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Fig. 5-28 Sound examples in different frequencies

Fig. 5-29 Sound examples in different loudness

Fig. 5-30 Talk in different reverberation time

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Fig. 5-31 A piece of music with and without reverberation

Fig. 5-32 Sound reflection video
Produced by ARUP

5.3 Second Part of the Debugging
The second part of the debugging was completed according to the comments and
experience provided by two architecture students and other two students from different
departments after using this program. It is the first time that they use this program. The
comments include the below contents:

Overall, the program works well. It is easy to understand and use. It can show any
results of calculations very fast. Bigger letters would be better for the Main Menu page.
95
(1) Basic Theory:
-Frequency, Period, and wave length section is good and easy to know, and calculator is
good.
-Sound intensity section has a nice picture to describe its content, and it is easy to
understand.
-The sound intensity level section has a good image to describe the knowledge.
-In the Loudness section, Loudness example works only on “1 X unit”, doesn't work on
“2 X unit” and “4 X unit” on the tester’s computer.
-Noise reduction section is brief but very easy to understand.
-Decibel addition is an important part in acoustic, it is good and necessary. It is good to
have this section in the program.

(2) Sound Absorption
In the room noise reduction with treatment section, NR calculator is good, but when
input over 10000sf for a wall, the result is strange. Some characters or some letters
cannot be seen.

96
(3) Room Acoustics
-In the Sound Reflection section, the video is very good to understand how sound
reflection works.
-In the Initial Time Delay section, the graphic and animation can explain the knowledge
very well, and they have exact description.
-In the Reverberation time section, program has good sound examples to feel the
reverberation time, but the louder sound would be better.

(4) Sound Isolation
-In the transmission loss and STC section, this program has a good image to describe
the content.
-In the mass law section, it is difficult to understand. It might have more explanation
for this section.
-In the noise reduction between rooms section, it would be better if there is more
explanation about the basic factors (TL, a2, and S).

97
(5) Electric Sound Systems
-In the loudspeaker systems section, the pictures are difficult to see. It would be better
if the pictures are clearer.
-Other parts in Electric Sound Systems section are easy to understand.

Base on the above comments, this program has been revised (See Chapter 4).
98
Chapter 6. Conclusions of this thesis and Future Work on AATT
6.1 Conclusions
The thesis presented an architectural computer-supported acoustics teaching tool AATT
which provides students a more interactive way of learning architectural acoustics
knowledge by visualizing and acousticianizing the theoretical knowledge into vivid
examples.

Students can study acoustics knowledge by reading books, however acoustics is a
science about sound, and it would be better to learn it combined with “hearing”.
Existing acoustical software programs, such as CATT-Acoustics and Ramsete, have the
primary function of room acoustics modeling, which can do simulations and design.
However those existing acoustical software tools are designed for professionals, who
have had some experience already, but not well suited for use by novices. Also they are
expensive or only available inexpensively as a demo version.

The AATT provided in this paper presents beginners who are learning acoustics an
effective way to learn acoustics with vivid experiences. It can be downloaded from
internet for free. The AATT program also can be updated easily by the author for future
99
development. The updated AATT program can be uploaded to a server and users can
download and update the program on their computer promptly.

This AATT program is base on basic architectural acoustics knowledge primarily
derived from existing written sources. The main book used to create this Architectural
Acoustics Teaching Software is “Architectural Acoustics” written by M. David Egan.
This book has seven chapters which are Basic Theory, Sound Absorption, Room
Acoustics, Sound Isolation, Mechanical System Noise and Vibration, Speech Privacy,
and Electronic Sound Systems. It gives basic concepts, practical computation and
design methods of architectural acoustics.

The AATT program covers main architectural acoustics knowledge, however does not
include mechanical system noise and vibrations. The mechanical system noise and
vibrations knowledge is for engineers who want to do acoustics design for mechanical
systems. So, in this thesis, they are not included.

The AATT is written using Visual Basic. 6.0 which is a convenient programming
language for creating graphical interface design. The main innovative features include
acoustical examples, animations, videos, interactive calculation function and graphics.
100
It can calculate reverberation time, sound absorption, initial decay time, sound
transmission loss, and other acoustics parameters when initial parameters are input by
users.

The AATT program can also use the ray-diagram analysis method to calculate the
initial-time-delay gap in rooms which have sound-reflecting ceilings when the sound
source position and receiver position are given.

The AATT can be visualized as a tree structure. It contains five basic sections, which
are Basic Theory, Sound Absorption, Room Acoustics, Sound Isolation, and Electronic
Sound Systems. Each part includes detailed branches and contents.

This thesis also includes a tutorial of the AATT program on Chapter 4. It presented how
to use this program in detail.

Chapter 5 presented the debugging for the AATT program. The debugging includes two
types. The first part of the debugging is performed according to some tests which were
finished by the author, including program installation test, basic error test, calculators
test and sound examples test. The second part of the debugging is finished according to
101
some experience and comments which provided by four students after using this
program.

6.2 Future work
Following the contents described in this thesis, some future improvements of this
program can be made.

Make this program more “fun”
This AATT program functions correctly but communicates information primarily with
engineering based images. To make this program more attractive to architecture
students, some interface re-design work can be considered.

Add more sound features
The most important and effective feature is that AATT contains several sound examples
which can let users have a more acoustical experience. Adding more sound examples
would make this program more attractive to users.

102
More program tests
The self performed test and the third party test are only the program function tests.
They are to ensure this program can work properly on the author’s computer and other
computers. It would be better to have a statistical survey or a rating system to test how
effectively students learn acoustics using this program.

Design an architectural acoustics website
This program only covers the basic architectural acoustics knowledge to suit the
students who are novices in acoustics. Some other complicated contents which are for
higher level people are not included. To make it better for more audience, it would be
better to design a website which can contain more architectural acoustics knowledge. In
addition, the AATT can also be uploaded to the website to provide access to more users.
103
Bibliography
Absorption (acoustics). (2009). Retrieved March 10, 2009, from Wikipedia, The Free
Encyclopedia: http://en.wikipedia.org/wiki/Absorption_(acoustics)

Acoustical Software. (2009). Retrieved March 10, 2009, from Acoustical.org, A Service
of the Acoustical Society of America: http://www.acoustics.org/software.html

Architectural acoustics. (2009). Retrieved March 10, 2009, from Wikipedia, The Free
Encyclopedia: http://en.wikipedia.org/wiki/Architectural_acoustics

CATT Acoustics. (2009). Retrieved March 10, 2009, from Acoustic Consultancy
Rahe-Kraft: http://www.rahe-kraft.de/cms/services/catt.en.htm

CATT-acoustic-modeling. (2009). Retrieved February 4, 2009, from Acoustic
Associates: http://www.acousticassociates.co.uk/catt-acoustic-modeling.htm

Egan, M. D. (2007). Architectural Acoustics. Fort Lauderdale, FL: J. Ross Publishing.
Enhanced Acoustic Simulator for Engineers - E.A.S.E. Software. (2008). Retrieve
d March 10, 2009, from Bright Hub: http://www.brighthub.com/engineering/mecha
nical/articles/17017.aspx

Jaffe, J. C. (2003). One approach to architectural acoustics in education. Acoustical
Society of America Journal , pp. V olume 113, Issue 4, pp. 2304-2304.

Kang, J. (2008, May). Computer tools for architectural acoustics education. The
Journal of the Acoustical Society of America , pp. vol. 123, issue 5, p. 3653.

Leo Beranek. (2009). Retrieved March 28, 2009, from The MIT Press:
http://mitpress.mit.edu/catalog/author/default.asp?aid=29955

Moy, J. (2002, Novermber). Efforts regarding acoustical education for architectural
students at the Universidad Peruana de Ciencias Aplicadas (Peruvian University of
Applied Sciences). The Journal of the Acoustical Society of America , pp. vol. 112, iss.
no. 5, p. 2236-2236.

104
NEMPEE Acoustics software. (2009). Retrieved March 10, 2009, from Nempee:
http://www.nempee.com/AcouSoft.htm

Reverberation Time. (n.d.). Retrieved March 10, 2009, from Department of Physi
cs and Astronomy, Georgia State University: http://hyperphysics.phy-astr.gsu.edu/H
base/acoustic/revtim.html

Visual Basic. (2009). Retrieved March 10, 2009, from Wikipedia, the free encyclopedia:
http://en.wikipedia.org/wiki/Visual_Basic

Abstract (if available)

Abstract This research aims to create an architectural computer-supported acoustics teaching tool AATT, which stands for Architectural Acoustics Teaching Tool. The AATT uses widely accepted principles and uses known algorithms. The goal is the creation of a digitalized tool that provides a more interactive way of learning architectural acoustics knowledge, by visualizing and auralizing the theoretical knowledge into vivid examples. The main innovative feature is that it integrates acoustics knowledge with acoustical examples, animations, videos, interactive calculation function and graphics. Most existing acoustical software tools, such as CATT-Acoustics and Ramsete, are aimed at professionals who already have significant acoustics experience. The tools are complicated to use and expensive to buy. Students need a free, easy to use teaching program which can provide basic knowledge about architectural acoustics. The AATT is written using Visual Basic. A tutorial is provided. Program debugging is also presented.

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Asset Metadata

Creator Xing, Tianxin (author)

Core Title A teaching tool for architectural acoustics

School School of Architecture

Degree Master of Building Science

Degree Program Building Science

Publication Date 04/30/2009

Defense Date 03/11/2009

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag architectural acoustics,digitalized program,OAI-PMH Harvest,teaching tool

Language English

Contributor Electronically uploaded by the author (provenance)

Advisor Schiler, Marc E. (committee chair), Milne, Murray (committee member), Noble, Douglas (committee member)

Creator Email txing@usc.edu,xingtianxin@gmail.com

Permanent Link (DOI) https://doi.org/10.25549/usctheses-m2159

Unique identifier UC1317001

Identifier etd-Xing-2788 (filename),usctheses-m40 (legacy collection record id),usctheses-c127-227843 (legacy record id),usctheses-m2159 (legacy record id)

Legacy Identifier etd-Xing-2788.pdf

Dmrecord 227843

Document Type Thesis

Rights Xing, Tianxin

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Repository Name Libraries, University of Southern California

Repository Location Los Angeles, California

Repository Email cisadmin@lib.usc.edu