发明名称 |
Noise reducing apparatus |
摘要 |
A noise reducing apparatus which is particularly effective to reduce periodic noise with the construction simplified very much is disclosed. The noise reducing apparatus comprises a microphone, an adaptive filter for generating a signal to reduce noise inputted to the microphone, transfer characteristic compensation means for generating a signal to compensate for a transfer characteristic when the signal generated from the adaptive filter comes the microphone, a synchronizing pulse generation circuit for generating a pulse signal synchronized with the period of the noise, a pulse interval detection circuit for detecting the interval between pulses of the pulse signal, tap number changeover means for changing over the number of taps of the adaptive filter to a number with which the delay amount of a tapped delay line of the adaptive filter is equal to the interval detected by the pulse interval detection circuit, and a loudspeaker for generating sounds in response to the signal from the adaptive filter. Also a noise reducing apparatus suitable for with an automobile.
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申请公布号 |
US5426704(A) |
申请公布日期 |
1995.06.20 |
申请号 |
US19930094449 |
申请日期 |
1993.07.21 |
申请人 |
PIONEER ELECTRONIC CORPORATION |
发明人 |
TAMAMURA, MANPEI;SHIBATA, EIJI;IIDAKA, HIROSHI;NOHARA, MANABU |
分类号 |
G10K11/178;(IPC1-7):A61F11/06 |
主分类号 |
G10K11/178 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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