To reduce the delay time of sound during a call and to prevent the deterioration of sound quality by selecting whether sound data is code.converted and is outputted to a base station or is outputted to the base station without code-converting it.

Sound data from a moving body exchange station 5 is sent to CODEC 41b and a sound type judgment part 61b in a down signal processing part 31h. CODEC 41b code-converts all sound into the sound of an attribute which the moving terminal 1b of an incoming side uses in spite of the attribute of the sound. When sound attribute information is added to sound data from a base station controller 3a, the sound type judgment part 61b gives an instruction to select sound data which does not pass through CODEC 41, namely, which is not code-converted, and to output it to the base station 2b to a sound selection part 62b. When sound attribute information is not added, an instruction to select sound data which passes through CODEC 41b, namely, which is code- converted and to output it to the base station 2b is given.