Feedback-cancelling electro-acoustic transducer apparatus
First Claim
1. An electro-acoustic transducer apparatus comprising a loudspeaker and microphone means having two closely spaced transducers, electronic circuit means, said circuit means including an additive circuit element and a substractive circuit element, each of said elements receiving output from both of said transducers, said elements providing two outputs one of which is wanted sound plus noise and the other of which is only noise, said circuit means comprising also phase adjustment means to receive said other output and to produce a noise component 180* out of phase with said other output, said circuit means comprising also means to combine said one output with said outof-phase component to cancel noise from said one output.
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Accused Products
Abstract
Electro acoustic transducer apparatus having a loudspeaker and one or two microphones includes positional and/or electric arrangements for reducing or cancelling feedback from the loudspeaker. Also, a microphone apparatus has positional and structural features for reducing or cancelling echo.
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Citations
3 Claims
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1. An electro-acoustic transducer apparatus comprising a loudspeaker and microphone means having two closely spaced transducers, electronic circuit means, said circuit means including an additive circuit element and a substractive circuit element, each of said elements receiving output from both of said transducers, said elements providing two outputs one of which is wanted sound plus noise and the other of which is only noise, said circuit means comprising also phase adjustment means to receive said other output and to produce a noise component 180* out of phase with said other output, said circuit means comprising also means to combine said one output with said outof-phase component to cancel noise from said one output.
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2. Apparatus as claimed in claim 1, and a housing mounting said loudspeaker and micropHone means together.
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3. Apparatus as claimed in claim 1, and an amplifier for the microphone means and an amplifier for the loudspeaker, and automatic gain control means for controlling the gain of the amplifiers.
Specification
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- Resources
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Current AssigneeSaad Zaghloul Mohamed Gabr
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Original AssigneeSaad Zaghloul Mohamed Gabr
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InventorsGabr, Saad Zaghloul Mohamed
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Primary Examiner(s)Brown, Thomas W.
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Application NumberUS05/425,527Time in Patent Office708 DaysField of Search179/1HF,1FS,81BUS Class Current381/93CPC Class CodesH04R 3/02 for preventing acoustic rea...
