The Acoustic Alphabet


The acoustic alphabetToday’s topic – the ABC Rule – is a common one in my field. I’ve literally presented it thousands of times, so I have to admit that I’m a bit weary of it. If you’ve heard it a few times before, you might be as well, but I encourage you to read on because I’m taking a slightly different approach in this post.

The traditional message is that controlling noise, providing speech privacy and creating a comfortable acoustic environment relies on three strategies – i.e. the ABCs. A is for Absorption. B is for Blocking. C is for Covering. I’ll speak to these methods in next week’s post. Right now, I’d like to focus on what’s missing from this alphabet: D for density, E for etiquette...and then skipping all the way to R for Reduce.

So, let’s begin at the end and work our way back...

Reduction is a key element of acoustical design. It addresses the noises in your space that simply don’t need to be there. Think of loud and endless ring tones, hands free phones, office or other equipment out in the open, improperly designed/balanced ventilation, and so on. Sometimes these sounds can be reduced or eliminated by the simplest interventions. For example, hospitals put padding at the bottom of clipboard racks to prevent the clicking made when the clipboards are dropped into place. The cost? Practically nothing. The impact? Huge.

Etiquette is really a subset of the reduction strategy, but it involves our ability to behave in an acoustically sensitive manner. There are habits we all fall into at one point or another that we should be more conscious of because they disturb others: having an impromptu meeting over someone’s workstation, talking to someone across the hall through your open doorways, leaving your phone ringer at emergency evacuation volume (and giving yourself a dozen rings to answer it). I’m sure you have your own pet peeves and know the offenders!

You may also have developed your own method of dealing with poor etiquette. My favourite example is an architect I know who works in an already acoustically-challenged office and has to resort to wearing headphones in order to get anything done (let’s call them her ‘Forget You’ headphones, per Cee Lo Green). She needs this crutch to focus on her job, but they offend her coworkers who see them as antisocial.

Next is Density. This feature has a critical impact on acoustics and our ability to control them, but it’s rarely included in the ABC discussion. The fact is, the tighter we space people, the tougher it is to design spaces that work well acoustically. In open plans, the average number of square feet per workstation has dropped dramatically in recent years. There’s not only less distance between people (meaning any noises they generate reach more listeners at higher volumes), but many more people within the same area (producing more noise overall).

Density is an interesting issue because the forces driving its increase are concerns such as high real estate costs and sustainability. Organizations placing more people into a smaller space should take greater care with acoustical design, but the current trend seems to be not only to increase density, but systematically eliminate most other methods of acoustical control – the ABCs that I’ll write about next week. Given that the long-term people costs far outweigh those of facilities in most markets, it’s worth questioning if this is the right course of action. But perhaps that’s a debate for another day...



Next week: How to address the ‘noises that remain’ using the ABCs.

Content coming soon.

© 2010-2024 K.R. Moeller Associates Ltd.

LogiSon, AccuMask, Archoustics, Task Masking, and Acoustic Comfort are registered trademarks of 777388 Ontario Limited. 
Patents granted in Canada, United States of America, Australia, China, Europe. Patents pending in United States of America, Canada and other jurisdictions.