Speaker damage prevention in adaptive noise-canceling personal audio devices

A personal audio device, such as a wireless telephone, includes noise canceling circuit (30) that adaptively generates an anti-noise signal from a reference microphone signal (ref) and injects the anti-noise signal into the speaker or other transducer output to cause cancellation of ambient audio sounds. A processing circuit (60) monitors a level of the anti-noise signal, determines that the anti-noise signal may cause damage to the transducer and adjusts the generation of the anti-noise signal such that damage to the transducer is prevented.