This week, my kids were off on March Break...and so was I. I really enjoyed spending time with them, doing fun activities. But I also took the opportunity to try to explain my job to them.
I don’t know if you had this experience growing up, but a lot of kids don’t really understand what their mom or dad do for a living. Our situation is further complicated by the technology my company manufactures. After all, how do you explain sound masking to a kid?
So, when we were on our way to swimming, an idea struck me. Everyone’s experienced masking of some sort. And by that, I don’t mean that they’ve necessarily worked in a building that had a sound masking system installed (although that probably applies to quite a lot of people). What I mean is that the masking effect occurs in a lot of daily situations.
Since we were driving in the car, I asked my kids if they’d ever noticed that it’s hard to hear what mom and dad are saying when we’re sitting in the front and they’re in the back seat. They might be able to tell that we’re talking, but they have a hard time actually following the conversation. That’s the masking effect. And it’s happening because the noise created by the car’s engine, road and wind have raised the volume of background – or ambient – sound in the car (probably to around 70 dBA, but I didn’t tell them that...one lesson at a time, right?), which interferes with their ability to hear other sounds. Because of the relatively high ambient volume, the masking effect works over a very short distance of just a few feet. The same thing happens in any vehicle with a raised background sound level, including an airplane, a train and even a space shuttle.
Running water is another common masker – from kitchen taps, to showers, to Niagara Falls. The sound of the running water raises the ambient level and covers up noises around you. I’m sure you’ve had the experience of rinsing dishes in the kitchen and needing to turn the water off to hear the person in the next room (or you can do the opposite...turn the tap on to drown them out).
These examples are all reasonably consistent sounds that extend over a wide range of frequencies, but other types of sounds will mask as well. In fact, any two sounds of similar frequency and volume will mask each other. Ever had trouble following two conversations at once? That’s at least partially because two people talking at the same time results in some level of masking. Music masks other sounds too, though only to a certain degree because a song’s volume will vary throughout the piece, and there may be moments of near silence in it as well. In other words, less consistent sounds provide variable (or, you might say, unreliable) levels of masking. This is also true for an HVAC system because it cycles on and off.
My kids pointed out that the examples are actually endless – waves breaking on the shore, wind blowing through the leaves, the murmur of a crowd in a restaurant, the dishwasher, the hair dryer, the lawn mower...all of these have the potential to mask other sounds around you.
So, now you too will be overly aware of all the examples of masking in your life. Welcome to my world!