Patent ID: 8126500

Claim:
A mobile communication apparatus usable for voice communication exchanging a received sound and a spoken sound, comprising: a first section; a second section movably connected to the first section in at least one of an ordinary mechanical mode and an extra mechanical mode; a detector configured to detect one of the ordinary mechanical mode and the extra mechanical mode; a speaker included in the first section and configured to produce the received sound; a microphone included in the second section and configured to pick up the spoken sound; an echo canceller configured to cancel an echo caused by leakage of the received sound into the microphone upon being provided with a signal of the spoken sound and a signal of the received sound, thereby producing an echo cancelled signal obtained by subtracting a signal of the echo from the signal of the spoken sound; an automatic gain control (AGC) circuit configured to receive the echo cancelled signal from the echo canceller to produce a gain-controlled signal based on the echo cancelled signal; and a controller configured to provide the AGC circuit with a first input/output characteristic and a second input/output characteristic in the ordinary mechanical mode and in the extra mechanical mode, respectively, wherein the second input/output characteristic is characterized by providing lower output than the first input/output characteristic in a relatively lower input level of the echo cancelled signal and by providing the same output as the first input/output characteristic in input levels other than the relatively lower input level of the echo cancelled signal.