PURPOSE: To cope with an increase in the number of divisions of a frequency band by increasing the number of elements formed as modules.

CONSTITUTION: This controller consists of an initial-stage element 31, a final- stage element, and at least one intermediate element 33. Namely, the speech signal which is digitized by an A/D converter 34 is supplied to the input port 3d of the initial-stage element 31. The speech signal and a corrected signal whose phase and amplitude are corrected by the initial-stage element 31 are outputted from the output port of the initial-stage element 31 and supplied to the input port 3d of the intermediate element 33. Similarly, elements are cascaded and a corrected signal after sound image control is outputted from the output port 3e of the final-stage element and converted by a D/A converter 35 into an analog signal. Any element is composed as a module by using a DSP (digital signal processor) having the same hardware, so the addition and specification alteration of elements are easy.