Cellular phone, and codec circuit and receiving call sound volume automatic adjustment method for use in cellular phone

摘要

Provided is a cellular phone enabling improvement of the level of a sense of hearing of a pseudo noise which is generated when there exists no voice signal. In the cellular phone, frame type information included in a baseband signal “in” is identified by the frame type identification unit 71 and when the frame type information represents pseudo noise information, a pseudo noise signal generated by the AMR (Adaptive Multi-Rate) decoder 72 with an internal pseudo noise generator is output to the call receiver unit 43 with its level reduced by a predetermined amount by the signal level change amount calculation unit 74 and the signal level change unit 73, while when the frame type information represents a voice signal, the voice signal decoded by the AMR (Adaptive Multi-Rate) decoder 72 with an internal pseudo noise generator is output to the call receiver 43 with its level unchanged.