Voice activated multiple microphone electroacoustic amplifier system
AssigneeU.S. Philips Corporation
InventorCornelis P. C. Nuijten
Life of this patent
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Abstract
An electroacoustic amplifier arrangement comprises a plurality of microphone arrangements each of which includes a microphone coupled to a comparator and coupled via a coupling circuit to a variable gain amplifier. The amplifier arrangement further includes a threshold signal generator. The threshold signal generator has a first and a second input coupled to the input and output, respectively, of the amplifier and is arranged to derive a threshold signal as a function of the signals applied to its two inputs. The output of the threshold signal generator is coupled to a second input of the comparator. The threshold signal generator is arranged to derive a threshold signal as a function of the gain factor adjusted in the amplifier.
Claims21
An electroacoustic amplifier arrangement comprising:
- a plurality of microphone arrangements, each microphone arrangement comprising a microphone with each of the microphones connectable to an input of an amplifier means having an adjustable gain factor and an amplifier output coupled to a loudspeaker arrangement for driving at least one loudspeaker associated with the loudspeaker arrangement, a threshold signal generator means for generating at its output a threshold signal, a microphone arrangement further comprising:
- coupling means for selectively coupling an output of an associated microphone to the input of the amplifier means as a function of the presence or absence respectively, of a control signal,
- comparing means having a first input coupled to the output of the microphone, a second input coupled to the output of the threshold signal generator means and an output coupled to a control signal input of the coupling means whereby the comparing means compares a microphone signal fed to the first input with the threshold signal fed to the second input and in response generates the control signal, and wherein the coupling means couple the output of the microphone to the input of the amplifier means in the presence of the control signal and to a further microphone arrangement of the electroacoustic amplifier arrangement, wherein the threshold signal generator means has a first and a second input coupled to the amplifier means and is arranged to derive from the signals applied to its first and second inputs a threshold signal as a function of the gain factor adjusted in the amplifier means.
An audio amplifier arrangement comprising:
- a loudspeaker arrangement including at least one loudspeaker,
- an adjustable gain amplifier means having an input and an output and with said output coupled to the loudspeaker arrangement for driving said at least one loudspeaker,
- a threshold voltage generator having first and second inputs coupled to the input and output, respectively, of said adjustable gain amplifier means so as to derive at its output a threshold voltage determined only by the gain factor adjusted in the amplifier means, and
- a plurality of microphone arrangements with each microphone arrangement comprising;
- a microphone,
- comparison means having a first input coupled to an output of the microphone and a second input coupled to the output of the threshold voltage generator, and
- switching means controlled by a control signal developed by said comparison means and operative to selectively couple the output of the microphone to the input of the amplifier means via a line common to at least one other microphone arrangement.
An electroacoustic amplifier arrangement comprising:
- a loudspeaker arrangement including at least one loudspeaker,
- an adjustable gain amplifier having an input and an output and with said output coupled to said at least one loudspeaker,
- a threshold voltage generator having first and second inputs coupled to said adjustable gain amplifier so as to derive at its output a threshold voltage signal determined by the gain factor adjusted in the adjustable gain amplifier, and
- a plurality of microphone arrangements with each microphone arrangement comprising;
- a microphone,
- comparison means having a first input coupled to an output of the microphone and a second input coupled to the output of the threshold voltage generator thereby to compare an output signal of the microphone with the threshold voltage signal, and
- switching means controlled by a control signal developed by said comparison means and operative to selectively couple the output of the microphone to the input of the amplifier via a line common to at least one other microphone arrangement.
Dependencies are inferred from the claim text.