This week, I’d like to speak to a common misconception about sound masking: the idea that it isn’t needed unless something’s gone ‘wrong’ with your facility’s design.
In our office, we call this the band-aid philosophy because it suggests that sound masking is merely a corrective measure you take after moving into your space and discovering the initial design or construction has somehow failed you acoustically.
While the number of subscribers to this viewpoint has dropped, a person I met with just last week suggested it. As usual, the concept came up when we were talking about closed offices. The person assumed that they’d achieve the desired levels of speech privacy and noise control if they built ‘adequate’ walls and provided ‘sufficient’ absorption. In other words, if they employed ‘good design’ and construction practices they wouldn’t need sound masking.
So, what’s wrong with this idea?
Well, as I’ve mentioned in previous posts, each method of acoustic control performs a unique role. Masking’s ability to control the background (or ambient) sound level simply can’t be provided by barriers or absorptive materials, just as a sound masking system can’t block or absorb noise.
Also, as you block out sound and reduce its energy using absorption, you also lower the ambient level in the space. Because the intelligibility of speech and the disruptiveness of noise are both related to the volume of the voice or noise compared to the ambient level (the signal-to-noise ratio), as ambience drops, you’ll hear more and more of even lower volume noises. In other words, you’ll create the proverbial ‘pin drop’ environment. And as you invest greater and greater amounts of your budget in barriers and absorptive materials, the ambient level will drop lower and lower. You’ll end up chasing your own tail – overinvesting with ever decreasing benefits.
Speaking of overinvesting...even those who promote this approach can’t always implement it. I remember a debate with industry colleagues many years ago over the then less accepted idea of using sound masking in closed spaces. When they raised the ‘good design’ argument and I opened my mouth to disagree, I noticed I could clearly hear the conversation in the next room. I couldn’t stop myself from pointing this out and asking why. Their response? “We couldn’t afford to build proper walls.”
The more effective approach (both financially and acoustically) is to include sound masking in your original design. Factoring in the control of background sound levels from the outset lets you properly balance all of the acoustic control methods in the space and get the maximum benefit for the minimum investment. For example, our sound masking clients have been able to eliminate high spec walls and plenum barriers while achieving as good or better privacy and substantial construction savings.
When designing for good signal-to-noise ratios, it’s best to work from both ends of the equation. I’m reminded of my marketing professor, Ken Wong, who said that to maximize profitability you need to think of your business as a Veg-O-Matic (recalling those late-night infomercials). In other words, you have to raise revenues and control costs. Not focussing on both elements yields less than optimal results.
If you try to achieve your goals with just two of the three methods of acoustic control, odds are you’ll not only end up spending more on those elements upfront, but more again in order to retroactively implement a sound masking system.