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What is Architectural Acoustics? – Making Spaces Sound Great!

When you walk into a concert hall, do you notice anything particularly different? Often times, audiences are instantly aware of the unique physical structure of a professional performance space, the moment they step through the entrance. If you want to know why these rooms are special, you must find out what is Architectural Acoustics!

People usually find themselves easily distracted (well, for me at least) by the aesthetic appeal of the various structural aspects of a live concert venue. Hence, it never really occurred to them that the design elements are there for an acoustical function, that benefits the overall experience of the musical performance!

Architectural Acoustics – A Primary Quality Factor

Otherwise known as “room acoustics”, architectural acoustics is a branch of acoustical engineering that deals with the science of achieving good sound quality within a building. Architectural acoustical methods was first applied by Wallace Sabine in the Fogg Museum lecture room. He then used his new found knowledge, to design the acoustics of the Symphony Hall in Boston.

Symphony Hall

The Symphony Hall in Boston / Photo by mooogmonster / CC BY-SA 2.0

Architectural acoustics is not only about enhancing the quality of sound in a concert hall or recording studio. Its principles are also used to achieve good speech intelligibility in a theatre or restaurant, and to make offices and homes more conducive and pleasant for people to work and live in. Architectural acoustic designs are typically carried out by acoustic consultants.

These are the topics that we’ll be looking into:

  • Building skin envelope
  • Inter-space noise control
  • Interior space acoustics
  • Mechanical equipment noise

Building Skin Envelope

Noise often travel through roofs, eaves, walls, windows, doors and penetrations. Hence, noise transmission from building exterior envelope to interior (and vice versa), must be analyzed. Having enough noise control measures in place, will ensure space functionality. These measures are also designed based on building use and local laws.

Birmingham Symphony Hall

Symphony Hall, Birmingham, an example of the application of architectural acoustics / Photo by Trevor Cox / CC BY-SA 3.0

A simple example would be coming up with an ideal acoustical design for a home which will be built close to a busy highway, or under the flight path of a major airport.

Inter-Space Noise Control

In order to ensure space functionality and speech privacy, noise transmission from one building space to another, must be limited or controlled. In these types of situations, sound often travel through ceilings, room partitions, acoustic ceiling panels (such as wood dropped ceiling panels), doors, windows, flanking, ducting and other penetrations.

Engineers will take into account the possible sources of noise and the path of acoustic transmission, before coming up with solutions. For instance, noise by steps or noise by flow vibrations (air, water). An example would be designing a party wall in an apartment, that will minimize the mutual disturbance due to noise by residents in adjacent apartments.

Interior Space Acoustics

This discipline involves controlling a room’s surfaces by utilizing sound absorbing and reflecting materials. Thus preventing excessive reverberation time, which can result in poor speech intelligibility. Reflections of sound waves create standing waves, which in turn produces natural resonances that can be perceived as a pleasant sensation or an unsettling one.

Culture Palace

Ceiling of Culture Palace (Tel Aviv) concert hall is covered with perforated metal panels / Photo by Etan J. Tal / CC BY-SA 3.0

The reflective surfaces of a room can also be beneficial if they are angled and coordinated in a way that provides good coverage of sound for a listener in a performance hall or music recital space. To understand this concept, try to observe the differences in design between a modern large office meeting room or lecture theatre and a traditional classroom with all hard surfaces.

Sound Absorbing Materials

There are many different materials and finishes used in acoustical treatments. The best acoustical panels are those without a face or finish material that interferes with the acoustical infill or substrate. Fabric covered panels are used to heighten acoustical absorption. Perforated metal sheets or plates also exhibit sound absorbing qualities, and are often used.

Sound Diffusers

“Diffusers” which scatter sound are also used in some rooms to improve the acoustics

Acoustical substrates are often covered over by various finish materials. “Mineral fiber board”, or “Micore”, is a commonly used acoustical substrate. Various finish materials often include fabric, wood or acoustical tile. Fabric can also be wrapped around substrates to create a “pre-fabricated panel”, which typically exhibits good noise absorption properties if laid onto a wall.

There are three ways to improve workplace acoustics and solve workplace sound problems – the ABCs.

  • A = Absorb (via drapes, carpets, ceiling tiles, etc.)
  • B = Block (via panels, walls, floors, ceilings and layout)
  • C = Cover-up (via sound masking)

Mechanical Equipment Noise

Building services noise control is the science of controlling noise produced by:

  • ACMV (air conditioning and mechanical ventilation) systems in buildings, termed HVAC in North America
  • Elevators
  • Electrical generators positioned within or attached to a building
  • Any other building service infrastructure component that emits sound.

If the noise generated by these equipment are not adequately controlled, it may lead to an unwanted increase in sound levels within the building, thus reducing speech intelligibility. Common control methods include vibration isolation of mechanical equipment, and sound traps in ductwork. Sound masking can also be created by adjusting HVAC noise to a predetermined level.

That’s about all I have for today folks. Do you notice any differences while working in an acoustically treated room?

Let me know your thoughts down below, and do share this article!

Farhan

When I'm not rocking out to great music, I'd prefer to be sleeping on a field on a windy day =)

8 Comments

  1. Wow, up until now I had only ever considered the Interior space acoustics as I’ve seen how none of the walls in a theatre run parallel to each other. It’s amazing how much has to be taken into consideration right from the start.
    I’d imagine trying to make a late fix can get pretty expensive.
    Does it take a special kind of architect to design buildings like this or do all modern architects have this kind of training?

    • Hi Ryan!

      The acoustic design for any performance space or room is done by acoustic consultants. Typical modern architects are normally not qualified for this kind of job. However, there is a high chance that acoustic consultants will have to work together with conventional architects when designing such places.

      Thanks for your thoughts!

  2. An interesting article; I consider that generally a lack of thought goes into dealing with sound in both indoor and outdoor spaces.

    Sound is shaped by space, and can contribute to the creation of spaces that are either warm and inviting or intolerably harsh.

    In addition, the physical form of the landscape can deflect sound to provide more amenable conditions for residents. A good example being the landscaping at Amsterdam’s Schiphol Airport.

    Thanks for your insight.

    • Hi there!

      Thanks for your input. Comments such as these, adds more depth to the article. Do come back for more content!

      Cheers!

  3. My family and I are wanting to put in a home movie theater in our basement, and want to make sure that it will have great sound inside and not so much sound on the outside of the room. I like the idea of using a party wall to minimize noise coming from the theater to help with the architectural acoustics. I think it would also be great to know if these are things we can put in ourselves or if it would be better to hire a professional. Thanks for clarifying what it is I would be needing for our future home project!

    • Hi Alex!

      Having your very own home movie theatre in a basement sounds like fun! Would love to see your home theatre once it is completed. Good luck with your project!

      Keep in touch =)

  4. I find that my work space carries noise easily which makes it hard to concentrate of work that needs to be done. Your article was very helpful in understanding why and how that can be fixed, or helped. Acoustical engineering is a profession I didn’t know existed but is one that is so important in the work place but also plays a huge part in the theater/ orchestra aspect. They understand sound waves and how it carries in a room which will then help with the way the room is built or fixed to aid in carrying/ stopping noise. If you have a consultant to walk you through what needs to be done to better improve a theater or your workplace, it would be very beneficial.

    • Hi Kourtney!

      Glad to know you have found this article to be educational. Thanks for sharing your thoughts!

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