| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for conveniently measuring an acoustic resistance value of an acoustic resistance material which is applied to an electroacoustic transducer, using an easy-to-carry and simple apparatus. SOLUTION: The apparatus includes: a sealing box 10, having an air chamber 11 of a predetermined volume in the inside and an opening 12 formed on a part; a dynamic headphone unit 20 hermetically fitted in the opening 12 with a diaphragm 21 directed toward the inside of the sealing box 10; an AC signal generating section 30 for supplying an AC signal of a predetermined frequency to a voice coil 213 of the diaphragm 21; and a voltage-measuring means 40 for measuring the voltage between both ends of the voice coil 213. An acoustic resistance material 1 to be measured is disposed so as to close the back-surface side of a magnetic circuit 23 of the dynamic headphone unit 20, the AC signal generating section 30 applies an AC signal of a predetermined frequency to the voice coil 213 to vibrate the diaphragm 21; the voltage-measuring means 40 measures the voltage between both the ends of the voice coil 213; and the acoustic resistance value of the acoustic resistance material 1 to be measured is measured, on the basis of the measured voltage. COPYRIGHT: (C)2011,JPO&INPIT
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