ABCs of Acoustics

Decibels, absorption, sound isolation, refraction, attenuation, transmission, nrc, tone, frequency. These are all terms often mentioned when discussing acoustics. These words seem very technical and perhaps that is where the trepidation of acoustics begins. I am not entirely sure. What I am sure of is that the way the sound (or noise) exists in a space is just as important as how it looks. I am sure you have been there. A busy noisy restaurant where you have to practically shout to your partner over a small table? Exhausted after a noisy flight? Attending your child's Christmas concert and not being able to hear what the principal is saying because of the audience and echo? What about having a heated personal conversation in a quiet office - where everyone can hear everything you say? Do you cover your mouth or go outside to the parking lot?

All these examples involve acoustics and how sound travels in a given space. Depending on what is the desired effect, we can manipulate the sound through three different methods to make all of the above environments function better.

The ABCs of acoustics are an easy way to remember the three types of solutions - often working in tandem to effectively improve the way a space sounds.

A- Absorption - this is the product we put into the space with ceiling tiles and baffles, wall panels, furniture, even people in the space absorb some sound. Sound gets emitted from the source and goes into the product, the material turns the sound to heat and absorbs it. Some sound will reflect back into the space and some sound will transmit further until physically blocked.

B - Blocking - a physical barrier prevents the sound from transmitting further. Think of a brick box (for illustration point) if someone was singing in a completely sealed brick box, you would not be able to hear them from the other side. Another way to think about Blocking is to imagine the space is full of water. Where does it escape? HVAC, under drafty doors and windows - even through electrical sockets. Anywhere that water would leak from, sound would also emit.

C- Covering - this is what you often hear as "white noise" - masking the noise in a space by use of sound generating equipment. Covering does nothing to the actual noise in the space, it merely adds to it making the source less clear.

Typically when a space is being designed is when the architect/designer will decide how to handle the Blocking. This is when physical barriers would be put up in the construction of the space. It is very important to note that no amount of absorption or cover will "fix" a blocking issue. However, once in the space, if there is echo or reverberation (due to materials in the space - ie: glass front walls, windows, hard surfaces, high ceilings etc) Absorption would be a great place to start. Our example of a restaurant or noisy gymnasium during a concert above would both benefit from absorption material. If the issue though is an already quiet office space full of cubicles perhaps Covering would be a great solution so that your colleague can't listen in to your heated argument with your spouse. Perhaps a phone booth or private call room with absorption product on the walls, and blocking in them would also be of benefit

For more information on acoustics and what we can provide you in Western Canada, please contact us!