PURPOSE: To realize the sound field controller from which no howling is caused due to feedback of an acoustic signal in the speaker microphone system.

CONSTITUTION: A circuit cancelling howling from a speaker 1 to a microphone 2 due to a reflection sound parameter is made up of a DSP7 and an FIR filter 8 and provided to the sound field controller in which a reflection parameter as to a reflection sound from a hall to be reproduced by the reproduction speaker 1 based on a reflection sound data in an acoustic space such as the hall is stored in a ROM 18 and a reflection sound signal corresponding to a source signal from the sound collection microphone 2 is generated by a DSP 7 based on the reflection sound parameter and fed to a speaker 1.