What is a sound masking system?
In general, the purpose of a sound masking system is to provide for greater conversational privacy and improved productivity in an open office environment by adding ambient noise and shaping the noise signal to mask speech. The noise signal is fed from a specially designed generator and amplifier to the SM speakers. Typically, these speakers are positioned out of sight above ceiling tiles in plenum space, although speakers with white enclosures are sometimes used in open architecture truss type ceilings. Sound masking speakers, generators, and amplifiers are typically sold separately.
How does sound masking work?
Many people mistakenly think that an electronic sound masking system magically gobbles up unwanted sounds. There have been a few products like those special headphones you can buy for air travel that actually do cancel out unwanted sounds. Although that can work in a very confined space like the headphone muff that covers your ear, that technology will not work on the scale of an open room.
Electronic sound masking systems do not gobble up sound at all. In fact, they do just the opposite. They actually add ambient noise to the area. The noise used is a specially filtered audio signal that is described by the NC-40 Contour. Increasing the ambient noise in an area effectively masks the spoken word because it makes it more difficult for speech to be heard and understood.
What is sound masking noise?
Electronic sound masking systems are often called “White Noise Systems” or “Pink Noise Systems.” Neither term is technically correct. White Noise (for audio use) is defined as “Equal sound energy at each frequency over the usable audio spectrum.” Pink Noise is defined as “Equal sound energy per octave over the usable audio spectrum.”
Note that by definition, an octave is a doubling of frequency, so between 20Hz and 40Hz is one octave, between 40Hz and 80Hz is one octave, and so on. That means that compared to White Noise, Pink Noise has much less energy in the higher frequencies than it does at lower frequencies. Since our ears work in a logarithmic manner, Pink Noise sounds “flat” to the human ear but White Noise sounds overly bright. In other words, because of the logarithmic nature of our human ears, it sounds to us like Pink Noise has as much energy in the low frequencies as there is in the high frequencies (even though that is really not the case).
Although electronic sound masking systems have been called “White Noise Systems” and “Pink Noise Systems”, a sound masking system doesn’t use white or pink noise but instead incorporates a very specific filtered noise (described by the “NC-40 Contour”) that has been proven scientifically to produce the maximum speech masking effect.
What does sound masking noise sound like?
Most people say it sounds like an air conditioning unit blowing. In fact, office workers have been known to put on sweaters and other extra clothing when a sound masking system is introduced to an office area because they think that the air conditioning unit is constantly running.
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