PURPOSE: To easily change an echo characteristic and to change the acoustic characteristics of an acoustic space by selecting the impressed voltage on electrode plates housing an ENC fluid compsn., removing the sound waves of the frequency band desired to be removed and reflecting the sound waves exclusive of this band.
CONSTITUTION: This echo adjusting device has the ENC(electrosensitive type sound wave adsorption controlling) fluid compsn. prepd. by incorporating EA particles having an EA (electric field arrangement) effect into an electrically insulating medium and a pair of the electrode plates housing the ENC fluid compsn. in this spacing and has sound wave absorption control plates 39a to 39c extended on the outer peripheral surfaces of columnar members 31 and a voltage impressing and regulating means 60 for impressing voltage between a pair of the electrode plates and regulating this voltage. The EA particles form chain bodies when the voltage is impressed between a pair of the electrode plates. These chain bodies resonate with the sound waves of the frequencies coinciding with the characteristic frequencies and absorb these sound waves. The sound waves of the other frequencies are reflected. The characteristic frequencies of the chain bodies themselves are made to coincide with the frequencies of the components desired to be removed by regulating the impressed voltage.
EDAMURA KAZUYA
GOTO MORITAKA
FURUICHI KENJI
OTSUBO YASUBUMI
FUJIKURA KASEI KK