Diver/above surface two way mobile telephone communication technique having adaptive system with microphone measuring presence/absence expelled air sounds and cancelling if present

摘要

The underwater sound processing method cancels sounds from the diver issuing air bubbles. The communications mechanism (10) has a microphone (17). The presence or absence of acoustic signals from expelled air is found, and a signal provided to cancel the background noise, if present, before transferring the communication to the surface.