Acoustic tiles, carpeting, and fabric-covered cubicles have helped to make the modern office a quiet place to work. But the lack of noise has the unintended effect of making even the smallest sound seem loud by comparison, distracting from the task at hand. Voices, in particular, can easily grab attention, making private conversations suddenly not-so-private. To address this issue, acoustics experts developed the technology of sound masking.

Sound masking acoustically floods an area with low-level background noise. The human brain responds by attempting to remove the background noise, simultaneously subtracting the sound of voices. This has the effect of making the individual words of background conversation less distinct.

Different types of random noise are used for sound masking. White noise sounds like the annoying static hiss created when a TV is tuned to a channel with no signal is one example. White noise has equal power within any equal interval of frequencies. Pink noise, on the other hand, is considered less irritating, as it gradually reduces the volume for higher sound frequencies. Pink noise is sometimes compared to the sound of a waterfall.

The random noise generated by the Contemporary Research SMG-40 Sound Masking Generator is purpose-built. Sound levels slope down from low frequency, leveling out at 200-600 Hz (the range of human speech), then sloping down again through higher frequencies. This approach creates background audio that is comfortable to hear, while simultaneously silencing background chatter to create privacy.

Many products provide sound masking. But the SMG-40 is the first product of its kind, providing a better experience than white or pink noise. The sound masking created by the SMG-40 provides privacy in offices, waiting areas, and other settings where confidentiality is needed and the American-made SMG-40 is easier to install than a ceiling apparatus.

Features of the SMG-40 include:

• Pink noise optimization for speech privacy
• Bass, treble and level adjustment
• Stereo music input and level control available for PA applications
• 3.5mm stereo music input with independent level control
• Drives speakers at 40 W RMS
• Dual RJ-45 outputs for Cambridge Qt Emitters
• 3-pin captive-screw terminal for 25V and 4/8 Ohm speakers or 8 Ohm/70V transformer
• Closure input to mute amplifier when activated
• Metal enclosure with flanges for surface mounting

Sound masking covertly introduces background noise to open office environments or other settings that require privacy. The sound piped in is used to distract individuals so they are less likely to hear all the conversations going on nearby. The standard of most traditional sound masking generators is pink noise, but the Contemporary Research SMG-40 offers a new option with bass and treble control that masks speech significantly better than pink noise.