Patent ID: 7965850
Filing Date: 2011-06-21
Classification: H04R

Abstract:
1. A method of detecting a resonant frequency comprising: a base step of measuring a base amplitude frequency characteristic; a first step of measuring a first amplitude frequency characteristic; a second step of measuring a second amplitude frequency characteristic; wherein the base amplitude frequency characteristic is an amplitude frequency characteristic obtained by outputting a sound wave of a specified measurement signal from a speaker disposed in a resonant space and by receiving the sound wave in a microphone disposed in the resonant space; wherein the first amplitude frequency characteristic is an amplitude frequency characteristic obtained by outputting, from the speaker, a sound wave of the measurement signal and a first delayed signal obtained by delaying a signal output from the microphone by first delay time that is not less than zero, and by receiving the sound wave in the microphone; wherein the second amplitude frequency characteristic is an amplitude frequency characteristic obtained by outputting, from the speaker, a sound wave of the measurement signal and a second delayed signal obtained by delaying the signal output from the microphone by second delay time that is not less than zero, and by receiving the sound wave in the microphone; wherein the second delay time is different from the first delay time; and wherein detecting the resonant frequency in the resonant space is based on the base amplitude frequency characteristic, the first amplitude frequency characteristic, and the second amplitude frequency characteristic.