What is a pilot tone?

Audio Solutions Team

Answer: Tone Lock™ squelch was discussed in our previous Question of the Week post and made mention of a pilot tone. The pilot tone is the “secret code” that is embedded into the wireless signal. The wireless receiver must confirm the presence of the pilot tone in the transmitter signal before it will open the audio circuitry through the squelch controls. This is essential to the wireless transmission as the presence of the pilot tone prevents the receiver from passing unwanted audio and noise. The pilot tone frequency is outside of the spectrum audible to humans and, hence, is not disruptive to any of the intended audio being wirelessly transmitted. This pilot tone feature is built into many popular Audio-Technica wireless products, including the 2000 Series. Additionally, digital Tone Lock squelch can communicate data from the transmitter to the receiver. The data often include the transmitter’s battery life and mute status for display on the receiver, as in the 3000 Series. Displayable naming functionality for the transmitters is also included with the digital Tone Lock squelch in the 4000 Series and 5000 Series. We hope this information helps further your understanding of what a pilot tone is and its role in enabling many features integrated into wireless systems. But, as always, if you require further assistance, please feel free to contact our Audio Solutions Department. Be sure to join us next time for another “Question of the Week”!