Automatic volume control for communication system

An automatic gain control for a cabin communication system for improving clarity of a voice spoken within a movable interior cabin having ambient noise includes a microphone for receiving the spoken voice and the ambient noise and for converting the spoken voice and the ambient noise into a first audio signal having a first component corresponding to the spoken voice and a second component corresponding to the ambient noise, a filter for removing the second component from the first audio signal to provide a filtered audio signal, an acoustic echo canceller for receiving the filtered audio signal in accordance with a supplied dither signal and providing an echo-canceled audio signal, a control signal generating circuit for generating a first automatic gain control signal in response to a noise signal that corresponds to a current speed of the cabin, the first automatic gain control signal controlling a first gain of the dither signal supplied to the filter, the control signal generating circuit also for generating a second automatic gain control signal in response to the noise signal, and a loudspeaker for outputting a reproduced voice in response to the echo-canceled audio signal with a second gain controlled by the second automatic gain control signal.