Hybrid expansive frequency compression for enhancing speech perception for individuals with high-frequency hearing loss
AssigneePurdue Research Foundation
InventorJoshua Michael Alexander
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Abstract
A method of audio signal processing comprising Hybrid Expansive Frequency Compression (hEFC) via a digital signal processor, wherein the method includes: classifying an audio signal input, wherein the audio signal input includes frication high-frequency speech energy, into two or more speech sound classes followed by selecting a form of input-dependent frequency remapping function; and performing hEFC including, re-coding of one or more input frequencies of the speech sound via the input-dependent frequency remapping function to generate an audio output signal, wherein the output signal is a representation of the audio signal input having a lower sound frequency.
Claims19
A method of audio signal processing comprising:
- (a) receiving an audio signal input via a digital signal processor, wherein the audio signal input includes a speech sound;
- (b) detecting a high-frequency energy of the speech sound via a detector of the digital signal processor to determine whether frication is present in the audio signal input;
- (c) when frication is present in the audio signal input, classifying the audio signal input into two or more speech sound classes, wherein the classification of the audio signal input includes:
- A) comparing a band-pass filtered energy of the audio signal input to a high-pass filtered energy of the audio signal input via the digital signal processor;
- B) selecting a form of the input-dependent frequency remapping function based on the comparison of the hand-pass filtered enercw and the high-pass filtered energy, wherein the form of the input-dependent frequency remapping function is at least one of:
- (i) compressive in the mid frequencies and expansive in the high frequencies, or
- (ii) expansive in the mid frequencies and compressive in the high frequencies;
- and
- C) selecting an expansive compression ratio (ECR) based on the selected form of input-dependent frequency remapping function;
- (d) upon classifying the audio signal input into two or more speech sound classes, initiating a Hybrid Expansive Frequency Compression (hEFC), wherein the hEFC includes re-coding one or more input frequencies of the speech sound via an input-dependent frequency remapping function to generate one or more output frequencies, wherein the output frequencies are at least one of:
- (A) first compressive and then expansive, or
- (B) first expansive and then compressive;
- and
- (e) generating an output signal from the output frequencies, wherein the output signal is a representation of the audio signal input having a decreased sound frequency.
A method of audio signal processing comprising:
- (a) classifying an audio signal input, which includes a frica ion high-frequency speech energy, into two or more speech sound classes by:
- A) comparing a band-pass filtered energy of the audio signal input to a high-pass filtered energy of the audio signal input via a digital signal processor;
- B) selecting a form of an input-dependent frequency remapping function based on the comparison of the band-pass filtered energy and the high-pass filtered energy, wherein the form of the input-dependent frequency remapping function is at least one of:
- (i) compressive in the mid frequencies and expansive in the high frequencies, or
- (ii) expansive in the mid frequencies and compressive in the high frequencies;
- and
- C) selecting an expansive compression ratio (ECR) based on the selected form of input-dependent frequency remapping function;
- (b) upon classifying the audio signal input into two or more speech sound classes, initiating a Hybrid Expansive Frequency Compression (hEFC) comprising a re-coding of one or more input frequencies of the speech sound via the input-dependent frequency remapping function to generate one or more output frequencies, wherein the output frequencies are at least one of:
- (A) first compressive and then expansive, or
- (B) first expansive and then compressive;
- and
- (c) generating an output signal from the output frequencies, wherein the output signal is a representation of the audio signal having a decreased sound frequency.
Dependencies are inferred from the claim text.