MICROPHONE SYSTEM BUILT IN DEVICE

摘要

PROBLEM TO BE SOLVED: To allow a microphone system which is built in a device, to hardly receive vibration of a mechanism section by making a learning operation of an adaptive filter stable. SOLUTION: A main microphone 1 that picks up a voice and a surrounding sound is fitted to an outside of a device. Furthermore, a noise referring microphone 5 that picks up a noise from the inside of the device is fitted to the inside of the device. Then an adaptive filter means 30 is used to suppress the noise. In order to make a learning operation of the adaptive filter stable against a noise source operated intermittently, a filter coefficient update control means 60 uses an output ratio of the main microphone 1 to the noise referring microphone 5 outputted from a level comparison means 50 and a control signal 90 driving a mechanism section to update a filter coefficient.