发明名称 |
NOISE-CANCELLING HANDSET |
摘要 |
A noise-cancelling telephone handset comprises a housing defining an earpiece (2) and a mouthpiece (3) housing a first order pressure gradient microphone (m). The housing is provided with two pressure-sensing locations (h1 and h2) in the region of the mouthpiece (3), these locations being connected to the microphone (m) by ducts (5). The pressure-sensing locations (h1 and h2) are spaced apart by a predetermined distance which is sufficiently large to permit locally-generated speech signals to produce a pressure gradient between the pressure-sensing locations whilst sound signals from distant sources produce substantially equal pressures at the pressure-sensing locations, whereby, in use, the output from the mouthpiece is substantially entirely that resulting from the locally-generated speech signals. |
申请公布号 |
WO9204792(A1) |
申请公布日期 |
1992.03.19 |
申请号 |
WO1991GB01513 |
申请日期 |
1991.09.05 |
申请人 |
BRITISH TELECOMMUNICATIONS PUBLIC LIMITED COMPANY |
发明人 |
HOLLIER, MICHAEL, PETER;WELSBY, KEVIN |
分类号 |
H04M1/03;H04M1/19;H04R1/40 |
主分类号 |
H04M1/03 |
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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