Hearing aid with digital compression recapture
First Claim
1. A hearing aid, comprising:
- an input to receive an input signal and output an analog signal;
a variable gain amplifier to selectively compress the analog signal;
an analog to digital converter receiving the analog signal and outputting a first digital signal;
a digital gain control to control gain of the variable gain amplifier;
a compression recapture system outputting a second digital signal that essentially represents a compressed portion of the analog signal;
an output to reproduce the input signal based on the first and second digital signals.
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Accused Products
Abstract
Systems, devices, and methods are provided to inhibit apparent amplitude modulation in non-linear processing that causes distortion in a processed signal. One aspect of the invention includes a hearing aid. The hearing aid includes a microphone to receive an input signal, a speaker to reproduce the input signal, and a processor. The processor processes the input signal using a gain. The processor includes an inhibitor, which inhibits distortions, and an adjuster, which adjusts the gain. The inhibitor acts to smooth an envelope of the input signal to inhibit undesired modulation. The adjuster adjusts the gain if the envelope is either above or below a threshold. The hearing aid further includes a compression recapture system to supply the compressed portion of the input signal to more closely reproduce the actual input signal.
84 Citations
19 Claims
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1. A hearing aid, comprising:
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an input to receive an input signal and output an analog signal; a variable gain amplifier to selectively compress the analog signal; an analog to digital converter receiving the analog signal and outputting a first digital signal; a digital gain control to control gain of the variable gain amplifier; a compression recapture system outputting a second digital signal that essentially represents a compressed portion of the analog signal; an output to reproduce the input signal based on the first and second digital signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of restoring a compressed signal in an input stage of a device, comprising:
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detecting when a first digital signal representative of an input signal is above a threshold value to produce a gain control signal; reducing gain of an amplifier to a value below the threshold value based on the gain control signal; and restoring an output signal of the input stage to include a compressed portion of the input signal the compressed portion of the input signal represented by a second digital signal, wherein detecting includes producing a digital gain control signal using a feed back approach.
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15. A method of restoring a compressed signal in an input stage of a device, comprising:
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detecting when a first digital signal representative of an input signal is above a threshold value to produce a gain control signal; reducing gain of an amplifier to a value below the threshold value based on the gain control signal; and restoring an output signal of the input stage to include a compressed portion of the input signal the compressed portion of the input signal represented by a second digital signal, wherein restoring includes applying an inverse of the gain control signal to restore the compressed portion of the input signal. - View Dependent Claims (16)
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17. An apparatus, comprising:
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an input to receive an input signal and output an analog signal; a variable gain amplifier to selectively compress the analog signal; an analog to digital converter receiving the analog signal and outputting a first digital signal; digital gain control means for controlling gain of the variable gain amplifier; compression recapture means for outputting a second digital signal that represents a compressed portion of the analog signal; and an output to reproduce the input signal based on the first and second digital signals. - View Dependent Claims (18, 19)
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Specification