Architectural Acoustics

Placeholder page for the supporting reference Architectural Acoustics, part of the Examitect reading list for the ExAC.

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Architectural Acoustics at a glance

Here's the at-a-glance summary an Intern Architect can scan before pulling the book off the shelf.

Full titleArchitectural Acoustics
AuthorMarshall Long
SeriesApplications of Modern Acoustics, edited by Moises Levy and Richard Stern
PublisherElsevier Academic Press
First edition2006 (a later Second Edition is also in circulation)
LanguagesEnglish
Primary audienceUpper-division undergraduate and introductory graduate students in architectural acoustics, plus practising architects and acoustic consultants
ExAC relevanceNot listed on Examitect's ExAC study plan. Extended reference behind several Section 3 supplementary documents on sound transmission and the NBC Part 9.11 acoustic provisions.
Where to accessUniversity and architecture school libraries; Elsevier and major academic booksellers carry the print and digital editions.

Why Architectural Acoustics matters for the ExAC

The ExAC asks acoustic questions even though it does not assign an acoustics textbook. Examitect's ExAC study plan lists two supplementary references on sound transmission for Section 3, Control of Sound Transmission through Gypsum Board Walls and Guide for Sound Insulation in Wood Frame Construction, both published by the National Research Council (NRC). NBC 2020 Part 9.11 sets minimum sound transmission ratings for housing. Long's book is the deepest single reference that explains the physics and assembly choices behind those documents.

You won't be tested on the math. You will be expected to recognize STC, FSTC, IIC, NRC, and reverberation time as concepts, know which one applies to which problem, and understand how an assembly choice (mass, separation, decoupling, absorption) changes the rating. Long's chapters 9, 10, 12, and 15 cover exactly that material, and his chapters on rooms for speech and on HVAC noise round out the design questions that come up in Section 1.

If you have time for one acoustics reference beyond the assigned NRC documents, this is the one most acoustic consultants point Intern Architects toward.

ExAC sections this reference supports

Section 1
Section 2
Section 3
Section 4

What Architectural Acoustics is

Architectural Acoustics is a technical textbook on how sound, vibration, and noise behave in buildings, written by Marshall Long, a practising acoustic consultant with decades of experience. The 2006 first edition was published by Elsevier Academic Press as part of the Applications of Modern Acoustics series. Long describes the book as a step-by-step progression through acoustic interactions, organized to support an upper-division undergraduate or introductory graduate course, with practical examples drawn from his consulting work.

The book runs roughly a thousand pages across 20 chapters. It opens with a historical introduction and the physics of sound, then moves through measurement, environmental noise, room acoustics, transmission through walls and floors, vibration isolation, mechanical and duct noise, and ends with chapters on the design of specific building types: multifamily housing, offices, rooms for speech, sound reinforcement, concert halls, and multipurpose auditoria.

Inside the book, the 20 chapters

Long groups the material into roughly five clusters. Knowing the shape makes it easier to skim what you don't need and slow down on what you do.

ChaptersWhat they coverExAC value
1 to 4
Fundamentals		 Historical introduction, frequency and wavelength, human hearing and perception, acoustic measurements, and noise metrics including NC, RC, and Leq curves. Background. Skip on first pass unless you want the physics.
5 to 7
Wave behaviour		 Environmental noise (traffic, rail, aircraft), wave acoustics and simple sources, and reflection and absorption at solid surfaces including NRC and impedance-tube measurements. Useful for the absorption coefficient discussion and for site noise context.
8
Sound in rooms		 Diffuse and semireverberant fields, Sabine and Norris-Eyring reverberation time, room effect, and reverberant falloff in long narrow rooms. Anchors reverberation time as a design parameter for classrooms, lobbies, and worship spaces.
9 to 10
Sound transmission		 Single, double, and triple-panel transmission loss; mass law and coincidence effect; STC, FSTC, and NIC ratings; common wood- and metal-stud partitions; exterior-to-interior transmission through walls, windows, and doors. Highest exam value. Sits directly behind the NRC sound transmission guides and NBC Part 9.11.
11 to 12
Vibration and floor noise		 Single-degree-of-freedom oscillators, isolator types (pads, neoprene, springs, hangers), inertial bases, floor vibrations, IIC ratings, footfall noise, structural deflection, and floor squeak. Backs the impact-noise side of party-floor design in multifamily projects.
13 to 14
Mechanical and duct noise		 HVAC equipment noise generation in fans, pumps, cooling towers, and emergency generators; flow noise in ducts; plenum attenuation, silencers, breakout and break-in noise; control of duct-borne noise. Supports engineering coordination questions and roof-mounted equipment layouts.
15 to 16
Multifamily and office building design		 Codes and standards for sound, party-wall and party-floor construction, flanking paths, electrical-box penetrations, plumbing and piping noise; speech privacy in open and closed offices and masking sound. Direct read across Section 3 Assemblies and Detailing and Section 4 office design.
17 to 18
Rooms for speech and sound reinforcement		 Reverberation, signal-to-noise ratio, articulation loss, Speech Transmission Index, classroom and conference-room design; loudspeaker systems, intelligibility, equalization, and computer modelling of sound systems. Programming-stage decisions for schools, lecture halls, and council chambers.
19 to 20
Rooms for music and multipurpose spaces		 Concert hall and opera house design, hall shape and volume, balconies, orchestra shells; multipurpose auditoria, sanctuaries, variable absorption and variable volume. Useful for cultural and worship-space programming questions.

If you are short on time, chapters 9, 10, 12, and 15 carry the heaviest exam load. Chapters 13 and 17 add value for engineering coordination and programming. The rest is depth.

Key acoustic terms every ExAC candidate should know

The ExAC reuses this vocabulary without redefining it. Learn the terms early so exam time goes to picking the answer, not parsing the question.

TermWhat it means
Sound Transmission Class (STC)A single-number rating of how well a wall, floor, or partition resists airborne sound transmission, measured under laboratory conditions per ASTM E90 and E413.
Field Sound Transmission Class (FSTC)The field-measured equivalent of STC. Accounts for flanking paths and workmanship variability that lab tests exclude. Typically lower than the lab STC for the same assembly.
Noise Isolation Class (NIC)A single-number rating of the actual noise reduction between two rooms in a finished building, including flanking transmission. Used when assessing complaints in occupied space.
Impact Insulation Class (IIC)A single-number rating of how well a floor and ceiling assembly resists impact noise such as footfall. Lab measurement per ASTM E492; field measurement per ASTM E1007.
Noise Reduction Coefficient (NRC)The average absorption coefficient of a material across the 250, 500, 1000, and 2000 Hz octave bands. Used to rate acoustic ceiling tile, wall panels, and other porous absorbers.
Reverberation time (RT60)The time for sound pressure level to decay by 60 decibels after the source stops. Estimated using the Sabine or Norris-Eyring equation from room volume and total absorption.
Sabine equationThe classical formula relating reverberation time to room volume and total surface absorption. Reasonably accurate for rooms with low to moderate absorption.
Speech Transmission Index (STI)A measured metric of speech intelligibility on a 0 to 1 scale. Higher values mean clearer speech. RASTI is the rapid variant used for room evaluation.
Mass lawThe principle that transmission loss through a single panel rises by about 6 decibels per doubling of mass per unit area. Underlies the rule that heavier walls block more sound.
Coincidence effectA frequency-dependent dip in transmission loss where the bending wavelength in a panel matches the acoustic wavelength, letting sound pass more efficiently. Limits how quiet a single-leaf wall can become.
Flanking transmissionSound that travels between two spaces along paths other than the directly separating wall or floor, such as continuous slabs, ducts, or structural framing. The reason FSTC is often lower than STC.
Resilient channelA thin metal channel that mechanically decouples drywall from studs or joists. Reduces structure-borne sound transmission and shows up in many higher-STC assemblies.

How Architectural Acoustics compares to other ExAC references

Long's book is the deep technical anchor. The assigned ExAC references give you ratings tables and code minimums. Use this comparison to decide which document answers which kind of question.

ReferenceWhat it's forHow Long's book relates
Architectural Acoustics (Long)Physics and design principles behind sound, vibration, and noise in buildings.The extended reference. Explains why the ratings are what they are.
Control of Sound Transmission through Gypsum Board WallsNRC technical guide on STC ratings for gypsum-board wall assemblies. Section 3 supplementary on Examitect's ExAC study plan.Long's chapters 9 and 10 explain mass law, coincidence, and double-panel theory; the NRC guide gives the rated assemblies.
Guide for Sound Insulation in Wood Frame ConstructionNRC guide on STC and IIC for wood-frame walls and floors. Section 3 supplementary on Examitect's ExAC study plan.Long's chapters 12 and 15 explain impact noise and party-floor construction; the NRC guide gives Canadian-specific ratings.
NBC 2020 Part 9.11The acoustic provisions in the National Building Code for housing: minimum STC and apparent STC between dwelling units.NBC sets the minimums; Long explains the assemblies that meet them and how flanking erodes performance.
CHING (Building Construction Illustrated)Diagrammatic reference for assemblies, materials, and detailing.CHING shows the typical assemblies; Long explains the acoustic performance of those same assemblies in detail.
Heating, Cooling, LightingBuilding services and mechanical design principles for architects.Long's chapters 13 and 14 add the noise side of HVAC: fan, duct, and equipment-room noise control.

How to study Architectural Acoustics for the ExAC

  • Skip chapters 1 through 7 on first pass. They are physics, history, and measurement. Useful background, but not direct exam content.
  • Read chapters 9 and 10 closely. Mass law, coincidence effect, STC, FSTC, NIC, and assembly types are the highest-value content for Section 3 sound questions.
  • Add chapters 11 and 12 for IIC, footfall, and floor vibration. These come up on multifamily party-floor questions.
  • Spend time on chapter 15. Party-wall and party-floor construction, flanking paths, plumbing noise, and electrical-box penetrations map directly to NBC Part 9.11 enforcement.
  • Cross-reference with NBC 2020 Part 9.11 and the two NRC sound transmission guides while you read. Long explains the why; the code and guides give the rated values.
  • Test recall with scenario-based practice questions on assemblies, party walls, and mechanical noise so the chapter content surfaces under exam conditions.

ExAC sections Architectural Acoustics supports

Examitect's ExAC study plan does not list Architectural Acoustics directly. The table below shows where the book is most useful in relation to the categories that do appear on the plan.

ExAC sectionWhere Long's book helps on Examitect's study plan
Section 1
Design and analysis		Programming and design-development decisions for classrooms, lecture halls, and worship spaces. Engineering coordination questions involving HVAC noise and equipment-room placement.
Section 2
Codes		Background for NBC 2020 Part 9.11 minimums on sound transmission between dwelling units. Long explains why the code numbers exist and what assemblies meet them.
Section 3
Sustainability and final project		Direct backing for the Assemblies and Detailing category. Chapters 9, 10, 12, and 15 sit behind the two NRC sound transmission supplementary references on Examitect's ExAC study plan.
Section 4
Construction and practice		Limited direct relevance. Chapter 15 on multifamily construction informs site-review judgment on party-wall and floor-ceiling assemblies during construction administration.

Tips for Intern Architects reading Architectural Acoustics

Long's book is written at a university level and runs roughly a thousand pages. If you're early in your internship under the Internship in Architecture Program (IAP) or its provincial equivalent, you need a sharper plan than cover-to-cover reading.

Tip 1, use it for the why, not the what. The assigned NRC guides give you the assembly tables. Long tells you why one assembly outperforms another. When a 2-hour wall gives you STC 60 and a similar wall gives you 45, the answer is in his chapter 9, not in the table.

Tip 2, skip the physics chapters. Chapters 1 through 7 build the theory from first principles. Unless you're curious about wave equations or impedance tubes, jump straight to chapter 8 on rooms, or chapter 9 on transmission. You can come back to the background if a chapter assumes too much.

Tip 3, pair chapter 15 with NBC Part 9.11. Long's multifamily chapter and NBC 9.11 are the strongest study pair for residential sound questions. Read them side by side so the code minimums and the assembly choices line up in your memory.

Tip 4, focus on mass, separation, decoupling, absorption. Most ExAC sound questions reward this mental model. Heavier mass and air space between leaves block more sound; decoupling with resilient channels or staggered studs cuts structural transmission; absorptive layers inside cavities help; flanking paths erode the rating.

Tip 5, learn STC vs IIC by feel. Airborne sound (talking, TV, music) is STC. Structure-borne impact (footfall, dropped objects) is IIC. The ExAC will not let you confuse the two and still answer correctly. Long's chapters 9 and 12 cement the distinction.

Tip 6, ask an acoustic consultant on a real project. Most architectural offices working on housing, schools, or theatres have a consultant on speed dial. Spending forty minutes walking through a project's acoustic report with one of them is worth more than another evening of reading.

Tip 7, don't try to memorize numbers. The ExAC will not ask you for the exact STC of a specific assembly. It will ask which assembly choice raises the rating, or what the architect should specify to meet a minimum. Read for principles, not values.

Common ExAC scenarios where Architectural Acoustics is the answer

These scenarios show up in different wording across ExAC sittings. If you recognize the pattern, Long's chapters tell you how to think about the answer.

  • A condo developer is failing a sound transmission test between two units. What assembly changes would the architect investigate first?
  • A school classroom feels echoey at the back of the room. What surface or volume changes would improve intelligibility?
  • A rooftop mechanical unit is generating tenant complaints in the floor below. What acoustic strategies belong in the design response?
  • An owner asks why specifying resilient channels and 5/8" gypsum on one side of a party wall costs more but is worth it.
  • A nursing home corridor is noisy enough that residents complain. What absorptive treatments help, and where do they belong?
  • A worship space wants live music and clear speech in the same room. What design parameters trade off between the two uses?
  • A duplex project is using a single 2x6 stud wall between units. What does NBC 9.11 require, and which Long chapter explains the workaround?

Each scenario traces back to a Long chapter. Chapters 9 and 10 handle airborne walls. Chapter 12 handles floor impact. Chapter 13 handles HVAC. Chapter 17 handles speech rooms. Chapter 15 ties them together for multifamily.

How Examitect reinforces acoustics

Reading Long is the deep dive. The other half of the work is recognizing acoustic patterns under timed conditions. Examitect's question bank includes scenario questions on STC, IIC, NRC, reverberation, and HVAC noise tied to NBC Part 9.11 and the NRC sound transmission guides. Each answer explanation points back to the relevant code section or chapter, so you can re-read just the few pages you need.

You also get scenario-based questions that put assembly choices into a real project context, full-length mock exams that mirror ExAC pacing, and free study notes for every section. Try a few sample questions first, then check pricing when you want the full bank.

Architectural Acoustics and ExAC FAQ

Architectural Acoustics is a 20-chapter technical reference written by Marshall Long and published by Elsevier Academic Press in 2006 as part of the Applications of Modern Acoustics series. It covers acoustic fundamentals, room acoustics, sound transmission, vibration isolation, mechanical and duct noise, and the acoustic design of multifamily, office, speech, and music spaces.

No. Architectural Acoustics is not listed on Examitect's ExAC study plan as a primary or supplementary resource. It is an extended reference that explains the physics and design principles sitting behind several supplementary references the study plan does list, such as Control of Sound Transmission through Gypsum Board Walls and Guide for Sound Insulation in Wood Frame Construction.

Section 3 (Sustainability and final project), specifically the Assemblies and Detailing category, is the most direct fit. Chapters on sound transmission, partitions, and floor noise help explain the STC and IIC values you will encounter in the assigned NRC sound transmission guides. Chapters on rooms for speech and music also support programming questions in Section 1.

The 2006 Elsevier Academic Press edition is the version commonly available. There is a later Second Edition; either edition covers the same architectural acoustics fundamentals the ExAC touches on, so the edition is rarely the deciding factor.

Skip the deep physics in chapters 1 through 7 unless you want the background. Focus on chapters 9 and 10 for sound transmission, chapters 11 and 12 for vibration and floor noise, chapters 13 and 14 for mechanical noise, and chapter 15 for multifamily party-wall and party-floor construction. Pair the reading with NBC 2020 Part 9.11 and the two NRC sound transmission guides on Examitect's ExAC study plan.

Sound Transmission Class (STC) rates airborne sound transmission through a wall or floor assembly. Impact Insulation Class (IIC) rates structure-borne impact noise, typically footfall, transmitted through a floor and ceiling assembly. NBC 2020 Part 9.11 sets minimum STC and apparent STC values for separating assemblies in residential buildings. Architectural Acoustics explains the physics and assembly choices behind both ratings.

It is a deep technical reference, longer than most ExAC candidates will need. Borrow it from a school or office library, read the chapters relevant to your current projects, and skip the rest. The investment makes sense for architects who design multifamily housing, schools, theatres, or sanctuaries, where acoustics drives real design decisions.

The ExAC focuses on architectural decisions, not acoustic engineering math. You should recognize STC, IIC, NRC, and reverberation time as concepts, know which ones apply to which problems, and understand how assembly choices change the ratings. You will not be asked to derive a Sabine reverberation time.

Keep exploring

Other ExAC reference books.

Architectural Acoustics is an extended reference. The core ExAC reading list runs through the six primary references below.

CHING

Building Construction Illustrated. The visual reference for assemblies, materials, and detailing across Sections 1 and 3.

CHOP

Canadian Handbook of Practice. The RAIC's practice reference covering most categories in Sections 1, 3, and 4.

NBC 2020

National Building Code of Canada. Part 9.11 carries the sound transmission provisions for housing.

NECB

National Energy Code of Canada for Buildings. Supports the envelope and energy questions in Section 2.

RSMeans

Construction cost data. Used for elemental estimating and cost-management questions in Section 1.

Supporting references

The extended reading list of supplementary references that show up across the ExAC reading list.