PURPOSE: To obtain a digital voice data phase converter arranged plural terminal equipments to be mutually independently driven and capable of transmitting voice data by adjusting a phase shift between both the equipments.

CONSTITUTION: A timing control part 18 receives a clock signal 1 and a synchronizing signal 2 outputted from a transmitting side equipment 21 and a clock signal 4 and a synchronizing signal 5 outputted from a receiving side equipment 22, and when the control part 18 detects the writing timing of the equipment 21, serial data 3 to be voice data are temporarily stored in a data storing part 16 through a serial/parallel(S/P) conversion part 15. When the control part 18 detects the reading timing of the equipment 22, the sound data stored in the storing part 16 are outputted as serial data through a parallel/serial(P/S) conversion part 17.