“Acoustics should be heard, not seen”, says Ivan Lin of LINSPACE, a professional consultancy in acoustics and audiovisual technologies for architecture and interior spaces. Moving beyond just limiting ambient noise, true acoustics is all about facilitating communication.  

Walls & Roofs sat down with him to find out more about this specialised discipline. 

The aesthetics vs function of acoustics 

The quality of speech delivery is where acoustics play a fundamental role. “Essentially, it’s all about communication. Why else would people gather in public spaces?” says Lin. The role of an acoustician is how to facilitate the design; not to change it but to make it work acoustically.  

More than absorption 

The phrase “soundproofing” is a misused term. Sound insulation and sound absorption are two different mechanisms; one is preventing the transfer of sound from one space to another, while the other is controlling reverberation within a space. Excessive reverberation is a key factor that destroys high-quality communication, the second being ambient noise. 

A combination of absorption, diffusion and redirection of sound is required to ensure effective communication within the space, be it a lecture hall, auditorium etc. 

Flexible acoustic design for The Edge Theatre, St Mary’s School 

By using a diffusive wall system, a diffusive stage area and a sound deflective ceiling, sound is redirected from the stage to a specific portion of the auditorium at St Mary’s School in Waverley. For an auditorium that needs to perform multiple functions, it can be designed with adjustable acoustics where the stage area can be changed to fulfil different acoustic conditions. 

One is sound reproduction via electronic mediums, where the sound can be conveyed by a microphone and reproduced with a loudspeaker. This gives the performers an environment that has much lower reverberation by using a combination of diffusion and absorption. 

Where there is no sound reproduction, the space becomes part of the performance, creating an acoustic environment that doesn’t need a microphone or loudspeaker to amplify the sound.  

Traditional products and modern versions 

Developed in the late 1800s, the original acoustic plaster consisted of wood chips, gypsum plaster and vermiculite; around the turn of 20^th century, vermiculite was often contaminated with asbestos, unfortunately. This has not been the case towards early 1980s. Early versions of rough acoustic plaster can still be seen in some older buildings and in basements, but it is not a very aesthetically appealing product, with a splattered visual effect and limited performance. This can be overcome by applying it in thicker layers, but the product is then more likely to delaminate. 

The current modern versions of acoustic plaster products provide a totally smooth surface, which gives an acoustic finish that doesn’t change the creative expression. The smooth finish can be coloured to add to the aesthetic value of the project. It is a very exciting development for the market, but it is a technical product and requires a trained applicator.  

Newer acoustic solutions 

Perforated gypsum was originally only available overseas, but as it was specified more and more locally, the market and availability grew. It is effective but it is also a challenging material to work with, as the joins need to be perfect to ensure that they are hidden and do not interfere with the required aesthetic of the space. 

The stretch-fabric system is a liberation creatively. A high-quality digital print is applied to a fire-rated polyester fabric, which can then be stretched across any span with a fibreglass layer behind. This system provides good acoustic performance and accommodates any design.  

Psycho-acoustician 

Acoustics is an art form, and even although there is a lot of technology currently being used, people’s understanding of acoustics is still growing. How you perceive sound is more complex that what science can tell you. Lin explains: “Our practice is more than being acoustician, we are psycho-acousticians. It is how we perceive sound that counts, more than theory, and calculation tells us.” 

Collaborative design 

Including sound design early in the design process allows acousticians to assist designers with a framework, especially when talking about space and geometry, to shape the space and to choose a design language in which aesthetic expression is incorporated. Early inclusion also ensures correct design that is within the budget. 

“Instead of being interior desecrators, acousticians can be part of the design team earlier than later. Creating spaces for people that are an integrated sensory experience of sight and sound in a holistic space.”
– Ivan Lin 

For more information, contact LINSPACE: 

Tel: +27 82 455 6141 

Email: office@linspace.co.za 

Website: https://www.linspace.co.za 

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