What does "squelch" refer to in radio communication?

The term "squelch" in radio communication specifically refers to the circuit that is designed to eliminate background noise when no signal is present. When a radio receiver is tuned to a specific frequency, there can often be unwanted noise or static that can interfere with reception. The squelch function allows the receiver to mute this noise so that the operator only hears the audio from a transmitted signal. This is particularly useful in ensuring that communications are clearer and that operators do not have to listen to unpleasant noise during periods of inactivity or weak signals.

The correct application of squelch enhances the overall efficiency of communication by ensuring that only meaningful transmissions are heard. By adjusting the squelch level, users can filter out weaker signals while still allowing stronger signals to pass through, leading to a more focused communication experience.