Sound Masking Definition

Sound masking is the process of adding a low level, unobtrusive background sound to an environment to reduce the intelligibility of human speech and reduce noise distractions in that environment.

The sound is typically introduced through speakers installed in or above the ceiling.

Sound masking and acoustic design

Sound masking is a critical component of acoustic design. When designing an optimal acoustic environment, architects consider a variety of elements to address noise control and speech privacy. Elements added either Absorb, Block, or Cover sound, and are collectively called the ABC’s of acoustic design.

 

All of the ABC’s of acoustic design can be used together or individually to achieve the desired acoustic environment, but absorbing materials (carpet, ceiling tiles, etc.) and blocking structures (walls, cubicle partitions, etc.) are costly and underused, particularly in modern offices. Sound masking, on the other hand, is a low-cost option for creating acoustical environments that both reduce noise distractions and protect private conversations.

 

 

How does sound masking work?

Sound masking works by a) raising the ambient noise level of an environment and b) making speech noise less intelligible and therefore less distracting.

Adding sound to a space actually makes the space seem quieter. It sounds counter-intuitive but it’s true. This is because the added sound reduces the intelligibility of human speech. When you can’t understand what someone is saying, their words are less distracting — in fact, you probably don’t even notice them.

Here’s an example of Sound Masking in everyday life. Have you ever had a conversation with someone while you are washing dishes and they are on the other side of the kitchen? When the water isn’t running, you can hear the other person’s words perfectly. When you turn the water on it becomes much harder to hear them and understand what they are saying. The person isn’t speaking more softly, but they sound as if they are. This is because the noise of the running water is “masking” the sound of the person speaking to you.

 

Sound masking mimics this phenomenon on a much more sophisticated and effective scale. By adding an ambient sound to an environment that’s specifically engineered to the frequency of human speech you can target conversational distractions and make them less distracting. Sound masking doesn’t eliminate all speech noise in an environment; it simply reduces the area where human speech is intelligible and distracting. We call this area the radius of distraction. Sound masking generally can cut down on the radius of distraction by a factor of 3 or more.