Voice operated switch
First Claim
1. A circuit for detecting the presence of voice energy in a composite voice and noise signal, comprising:
- means for separating the voice signals from the noise signals to produce an indication of the presence of said voice signals, including;
means for producing an envelope waveform of the composite voice and noise signala syllabic rate filter for extracting the syllabic rate content of the voice signal from said envelope waveform, andmeans, including an amplifier, for amplifying only acceptable syllabic rate content exceeding an offset threshold and thereby discriminating against unacceptable syllabic rate components, said amplifier having the majority of the circuit gain such that the output thereof is driven to one state during the presence of said acceptable syllabic rate content, and said output is driven to another state during the absence of said acceptable syllabic rate content;
whereby said one state is representative of the presence of voice signals and said other state is representative of the absence of voice signals.
1 Assignment
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Accused Products
Abstract
A voice operated switch having minimum signal amplification in the stages which separate the voice signals from the noise signals. The majority of amplification is then applied only to the syllabic rate voice component detected by an offset threshold in the syllabic rectifier-amplifier circuit to produce a two-state signal, one state representative of the presence of voice energy and the other state representative of the absence of voice energy. The two states are compared with a threshold voltage adjustable between a maximum and minimum voltage. A maximum and minimum setting allow a respective nontransmission and transmission of the voice signals irrespective of the presence or absence of such signals.
34 Citations
8 Claims
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1. A circuit for detecting the presence of voice energy in a composite voice and noise signal, comprising:
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means for separating the voice signals from the noise signals to produce an indication of the presence of said voice signals, including; means for producing an envelope waveform of the composite voice and noise signal a syllabic rate filter for extracting the syllabic rate content of the voice signal from said envelope waveform, and means, including an amplifier, for amplifying only acceptable syllabic rate content exceeding an offset threshold and thereby discriminating against unacceptable syllabic rate components, said amplifier having the majority of the circuit gain such that the output thereof is driven to one state during the presence of said acceptable syllabic rate content, and said output is driven to another state during the absence of said acceptable syllabic rate content; whereby said one state is representative of the presence of voice signals and said other state is representative of the absence of voice signals. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A voice operated switch for enabling or disabling a transmission channel in response to the respective presence or absence of voice signals, comprising:
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envelope detector means for detecting the envelope of composite voice and noise signals; syllabic filter means for generating syllabic rate signals corresponding to the syllabic content of said envelope; amplifier means for amplifying said syllabic rate signals an amount sufficient to produce a first output state, and a second output state in response to the absence of said syllabic rate signals; offset threshold means for preventing said amplifier means from amplifying syllabic rate signals falling below a predetermined amplitude; and a comparator for comparing the output state of said amplifier with an adjustable reference potential, the maximum potential thereof being greater than said first output state, wherein an adjustment thereto disables said transmission channel, and the minimum potential thereof being less than said second output state, wherein an adjustment thereto enables said transmission channel.
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Specification