Silenceable speaker with pre-announce tone detection

A silenceable communication system receiving signals from a signal source, the silenceable communication system comprising:

• a sound producing device coupled with driver circuitry, the driver circuitry receiving the signals, the sound producing device being operable in combination with the driver circuitry to produce sound in response to the signals;
• a silencing circuit coupled with the driver circuitry and operable to temporarily decouple the sound producing device from the driver circuitry such that no sound is produced by the sound producing device, the silencing circuit comprising
• an input device operable to provide input;
• a timing circuit operable in response to the input to produce a de-activation signal for decoupling the sound producing device from the driver circuitry such that no sound is produced by the sound producing device, the timing circuit being further operable to measure a pre-established period of time and then produce a reactivation signal for re-coupling the sound producing device to the driver circuitry;
• and
• a latch operable in response to the de-activation signal to decouple the sound producing device from the driver circuitry, and in response to the reactivation signal to re-couple the sound producing device to the driver circuitry;
• and
• a reactivation circuit coupled to the silencing circuit and operable to re-couple the sound producing device with the driver circuitry upon receipt and identification of a pre-announce signal sent by the signal source, the pre-announce signal having at least one particular identifying characteristic, the reactivation circuit comprising circuitry operable to identify the pre-announce signal by its particular identifying characteristic.