Architects generally receive little, if any, education in acoustics. In formulating design goals for projects, acoustics is a low priority – except when it is fundamental to a building’s function (e.g. a concert hall). This is a missed opportunity. Great aural environments can be transcendental. Acoustics is the invisible art. When done well, spaces feel right – elevating one’s experience. Get it wrong and it can make buildings unfit for purpose. Poor acoustics can be expensive, difficult or impossible to correct once you have them. It requires integrated thinking from the start.

Saskatchewan Hospital, North Battleford. BAP Acoustics worked with Access Prairies Partnership – the consortium comprising Graham Design Builders and Carillion Canada – to provide acoustic design advice to the team lead by Kasian Architecture and WSP Canada.
North Battleford-based Saskatchewan Hospital ranks among the most advanced mental health treatment centres in Canada. BAP Acoustics advised the Kasian Architecture & WSP Canada-led design & build team on acoustic design. Our services included: Sound Insulation (STC) Control; Reverberation Control; Building Services Noise Control; Vibration Isolation Design; Building Services Noise &/or Vibration Assessment; Environmental Noise Monitoring & Assessment; Specification/Contractual Compliance Testing; and Acoustic Design for Design & Build and P3 Projects.

Sound behaviour: why architects & designers need to know about it

Whether we’re discussing office towers, theatres, schools, houses, multi-family residential buildings, or hospitals, the acoustic characteristics of any enclosed space can profoundly impact the comfort and productivity of those within. The proper implementation of acoustic design principles is key to creating an environment that’s not only aesthetically pleasing but also conducive to occupant well-being.

And—particularly if you’re a music lover—you’ll agree that aesthetics encompass far more than what we see around us. Sounds have unique aesthetics of their very own, some more subjectively “pleasing” than others… But this is neither the time or place to tell you about that year my little brother tried to learn to play violin in grade school.

In Part 1 of this series, we noted that the branch of acoustical engineering known as architectural acoustics refers to both the study and control of indoor sound behaviourand most acoustical consultants credit American physicist Wallace Clement Sabine for pioneering their field in the late 1800s.

"Where's a guy gotta go to hear himself doom-scroll around here?" (Photo: Tim Gouw)

Naughty sound waves caught literally bouncing off walls!

Understanding the science behind the behaviour

When sound—audible pressure wave energy moving through air or any other medium—impinges on a building interior surface, some of the energy passes through it, some is absorbed, and some is reflected.

Absorbed sound energy turns into heat within the surface material, but you can’t actually heat up a wall hot by yelling at it…which is really too bad. I mean, we could mitigate both energy AND psychological crises through primal scream therapy!

“It’s not that much heat,” explains an Amber Book video narrator in Architectural Acoustics 1 of 4: Sound and Building Materials.

When impinged upon by sound energy, molecules that form a given building material move around; and as they rub together, they lose some of that energy through friction.

Finally, some of the sound energy is reflected. All three reactions—transmission, absorption, and reflectionoccur simultaneously,.

My dear Watson, material is anything but immaterial!

The reverberation of noise (aka unwanted sound) from walls and ceilings essentially amounts to sound waves reflecting off surfaces—just like a ball bouncing around inside a squash court. The more reflective the receiving surface, the longer it takes for sound to fade away or “decay“, and we perceive this phenomenon as “noisy” or “echo-y”… not to mention downright annoying when accompanied by your squash opponent’s victorious woo-hoos!

Acoustically absorbent materials, on the other hand, help dampen reverberance levels in indoor spaces, thereby reducing excessive sound build-up and echo.

All materials transmit, absorb & reflect sound:

This is a function of the material mass, surface smoothness, fibre orientation, porosity, air tightness, and stiffness.

Source: Architectural Acoustics Illustrated, by Michael Ermann

Examples of building materials and how they affect the movement of sound include:

  • Glass. Characterized by low mass and negligible pores, glass allows very little transmission or absorption of sound but reflects a significant amount.
  • Smooth concrete. With considerable mass and an airtight quality, this material also reflects high levels of sound energy while absorbing and transmitting very little.
  • Concrete + a layer of fabric wrap glass fibre. Substantial mass mitigates sound wave transmission through the concrete layer, while the porous glass fibre layer absorbs that energy like steaming mashed potatoes do butter. As a result, very little sound is reflected or transmitted in this composite construction. And good job, mashed potatoes! You’re top-notch eating material. 😋


The takeaway here? A good understanding of how building materials interact with sound waves—their order, orientation and type—is essential for architects and designers. Knowing which materials are best suited to various acoustic environments, along with their specific absorptive features, is crucial in designing occupant-friendly and purpose-aligned acoustic spaces.

In Part 3 of this series, we’ll delve a little further into sound wave characteristics, as well as look at strategies for helping architects and designers create acoustically purposeful indoor spaces to meet occupant needs and tangibly contribute to their well-being. Until then, may the good sounds be yours as you consider these closing words:

While it’s okay to be angry at misbehaving drywall, shouting at it will only p*ss off whoever’s on the other side. (Especially if said wall hasn’t been sound attenuated.) As for punching it? Well, that’s gonna hurt you way more than it’ll hurt the drywall!

Denny Ng, M.A.Sc. P.Eng.

Senior Acoustic Consultant

Denny is a locally trained and licensed Professional Engineer specializing in environmental noise modelling, architectural acoustics and mechanical noise control. His career as a consultant began with an internship at BAP Acoustics in 2016 while completing his graduate studies in acoustics at the University of British Columbia. Working closely with Eric and Mark, Denny has had the privilege of working on numerous post-secondary education and infrastructure projects including Emily Carr University of Art and Design, UBC Gateway and Brock Commons Phase 2, Stuart Lake Hospital Replacement Project and Nanaimo Correctional Center. His approach to consulting is communicating acoustical concerns as they arise in order to reach cost effective solutions. 

 

Qualifications

B.A.Sc. Mechanical Engineering – Thermofluids Option (with distinction), University of British Columbia, 2014

M.A.Sc. Mechanical Engineering – Acoustics Group, University of British Columbia, 2019

P.Eng. BC

Leanne Farmer, B.Eng.

Acoustic Consultant

Leanne Farmer began her career in Adelaide, where she gained four years of experience providing acoustic design advice across Australia. She possesses extensive technical knowledge in both building acoustics and complex environmental noise assessments. Demonstrating her capabilities in multi-disciplinary coordination and project management, Leanne effectively managed large-scale measurement campaigns and contributed to major infrastructure projects. After re-locating back to Victoria, BC in 2023, Leanne joined BAP Acoustics. She is excited to be working on local projects, applying the experiences and insights gained from her diverse international work.

 

Qualifications

B.Eng. Mechanical Engineering, University of Victoria, 2018

EIT, BC

Alex Mendes, B.Eng. EIT

Acoustic Engineer

A graduate of the University of Victoria, Alex has contributed to an array of computerized acoustic modelling projects during his tenure with BAP Acoustics. His passion for music lends itself to a particular focus in room acoustics modelling, where he has applied creative approaches to navigate the unique challenges posed by varied architectural designs. His expertise extends to outdoor sound modelling, where he has lent his skillset to initiatives ranging from shooting noise control studies to public alert system performance evaluations. Alex’s ardent curiosity and his analytical, pragmatic approach to consultation have served him well in providing sensible, practical solutions to a host of acoustic challenges.

 

Qualifications

B.Eng. Mechanical Engineering, University of Victoria, 2018

EIT, BC

Kathryn Gulewich, B.Eng. EIT

Acoustic Engineer

Kathryn is a Mechanical Engineer who graduated from the British Columbia Institute of Technology (BCIT) with a Bachelor of Engineering degree. She pivoted to the field of acoustical consulting upon joining BAP Acoustics in 2022, embracing a transition marked by rapid expertise accrual—particularly in outdoor noise monitoring and HVAC noise control. Kathryn’s solid engineering background supports her technical approach to acoustic challenges, blending mechanical engineering principles with the specialized demands of acoustic consultancy.

 

Qualifications

B.Eng. Mechanical Engineering, BCIT, 2011

Nicole Yeung, M.Eng. EIT.

Acoustic Engineer

An Honours graduate, Nicole earned her M.Eng. degree in Acoustical Engineering at the globally renowned Institute of Sound and Vibration Research founded 60 years ago by the UK-based University of Southampton. Nicole’s project experience encompasses acoustic design, implementation and testing at all stages of work. Her project contributions include examining and optimizing: sound insulation between spaces; room reverberation time; and mechanical noise emissions. She is also experienced in outdoor noise propagation simulation and environmental noise study for: new residential developments; fitness facilities; office buildings; and industrial developments. Nicole has a strong foundation in outdoor noise propagation software Cadna/A. In addition, she is experienced in using programs such as Insul for sound insulation prediction and ODEON for room acoustics. 

 

Qualifications

M.Eng. Acoustical Engineering (Honours), Institute of Sound & Vibration Research, University of Southampton, UK.

EIT, BC