| 摘要 |
A throat microphone has an outer resonant diaphragm which is adapted to be secured against the throat of a wearer and which cooperates with a housing to form an outer chamber. An electret microphone element disposed inside the outer chamber includes an electret diaphragm acoustically coupled to the outer diaphragm and an electret housing forming an inner chamber with the electret diaphragm. The electret diaphragm is perforated to provide pressure relief between the two chambers to give the electret microphone element a rising response characteristic, which is enhanced by a differentiating network in the input circuit of a local preamplifier. The outer diaphragm is so formed as to have a principal resonance at about 3 kilohertz to provide a further emphasis to voice frequencies at or near that resonance.
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