| 摘要 |
PURPOSE:To obtain directivity characteristic over a wide band by dividing an object frequency band into plural bands, forming an array microphone with a narrow band and adding outputs of the microphone. CONSTITUTION:An A/D converter means 12 converts a sound wave from a microphone unit 11 into a digital signal at a sampling period, a two-dimension digital filter 13 applies two-dimension convolution processing to the signal and a band pass digital filter 16 passes the signal of the directivity band. An A/D converter means 22 converts a sound wave of a microphone unit 21 into a digital signal at a sampling period, a two-dimension digital filter 23 applies two-dimension convolution processing to the signal and a band pass digital filter 26 passes the signal of the directivity band. When outputs of the band pass digital filters 16, 26 are added by an adder 3 and the directivity band is the synthesis of the frequency bands of a high frequency array microphone 1 and a low frequency array microphone 2. Thus, the directivity over a wide band is realized. |
