Patent ID: 8150045
Filing Date: 2012-04-03
Classification: G10L,H03G,H04M

Abstract:
1. An automatic gain control system applied to a audio signal as a function of the ambient noise, the system comprising: a variable-gain amplifier receiving said audio signal and suitable to adjust the volume of a signal outputted by a loudspeaker, an ambient noise estimator module suitable for establishing a current noise value estimated at least from a signal provided by a microphone; and an automatic gain control module suitable for determining a gain value to be applied by said amplifier to said audio signal; wherein: the ambient noise estimator module comprises an MCRA estimator suitable for extracting, from the signal provided by said microphone including real noise, echo of the audio signal and speech if any, a value of the ambient noise component on its own after the speech component has been eliminated; and the system further comprises a module for estimating the power of the audio signal and suitable for providing the automatic gain control module with a current power value for the audio signal.