Squelch

A function found on some radio receiving systems such as wireless microphones and guitar units that allow the user to set the receiver to mute or gate itself when the carrier falls below a specified level. The idea is to eliminate the unwanted noise associated with a radio receiver being tuned between stations, or not properly picking up a station/transmitter to which it is tuned. Typically turning the squelch control “up” makes the receiver have more of a tendency to mute, which means the carrier strength has to be higher in order for it to operate. If the squelch is set too high the audio will mute from time to time, however, if it is set too low you run the risk of getting blasts of noise through the system when the signal strength is compromised for one reason or another. The squelch control was an important part of wireless systems for many years, but with modern technology there are more sophisticated and automated methods of handling these things, which have all but eliminated the manual squelch control from systems.