When I tour projects, I continue to be impressed with our sound masking system’s impact on speech privacy and noise control. Of course, I have an advantage: a thorough understanding of how this technology works and how it fits into the overall acoustic design.
But this isn't necessarily true for all sound masking clients. The risk in our business – as in most others – arises if a customer has unrealistic expectations. For example, if they think the system will activate a ‘cone of silence’ around them, then no matter how well the masking performs, they’ll be underwhelmed. It’s the classic mismatch between expectations and reality.
So, I thought it would be good to provide an idea of what you should expect to experience if you install sound masking in your facility...and why.
First, sound masking’s impact is dictated by physical laws. And no matter how much we might like it to, technology isn’t able to defy those laws.
Essentially, masking takes advantage of the signal-to-noise ratio. It raises the background level (the ‘noise’) in order to provide an ambient volume that’s higher relative to the level of unwanted sounds (the ‘signal’). Masking’s effect kicks in as the volume of those unwanted noises approaches the level of the masking sound and increases as they meet or drop below the masking’s volume.
In other words, masking either covers the noises completely or reduces their impact on occupants by decreasing the amount of change between the baseline and peak volumes. The masking system controls the baseline in the space.
But the noises you want to mask are outside of the system’s control. Their volume is determined by their source as well as the impact of other elements of the acoustical design, such as blocking and absorption (see A Beautiful Combination, February 17, 2012).
This brings me to my second point. Just as you car’s horsepower isn’t the only determinant of how fast it goes (vehicle weight, aerodynamics and traction also come into play), the overall acoustical performance of your space isn’t determined by sound masking alone...or, in fact, by any other individual product or strategy. Rather, it’s the combined effect of all the design (not to mention, behavioral) strategies used within it. The less the contribution made by any strategy, the less the overall design is capable of achieving. Though installing a sound masking system can help make up for missing elements or ones that aren’t quite performing up to snuff, it isn’t a silver bullet.
Join me next week for Part II of this post!
Cheers,
Niklas