Time-limited electrical audio signals are fed to an electromechanical output transducer in addition to the signals from the hearing aid input. Some of the time-limited audio signals are user-defined. The process is implemented in a hearing aid having an electromechanical transducer and a signal processor....http://www.google.de/patents/US7149319?utm_source=gb-gplus-sharePatent US7149319 - Telecommunication system, speech recognizer, and terminal, and method for adjusting capacity for vocal commanding
