A method of detecting a noise level from audio signals produced consecutively in time by a microphone. The method includes the steps of evaluating an average level of the audio signals consecutively in time, and selecting the smallest of the average levels as the noise level. A telecommunication apparatus...http://www.google.de/patents/US6125288?utm_source=gb-gplus-sharePatent US6125288 - Telecommunication apparatus capable of controlling audio output level in response to a background noise
