# US 2021/0280203 A1 · Voice Signal Enhancement For Head-Worn Audio Devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0280203 A1 - Document ID: US20210280203A1 - Status: Published application - Kind: A1 - Application number: 17/330,011 - Filed: 2021-05-25 - Published: 2021-09-09 - Earliest claimed: 2019-03-06 - Assignees: Plantronics, Inc. - Applicants: Plantronics, Inc. - Inventors: Shridhar K. Mukund; Pamornpol Jinachitra - Web page: https://patentgrep.com/patent/US20210280203A1 ## CPC - G10L 21/0208: Noise filtering - G10L 21/028: using properties of sound source - G10L 21/0232: Processing in the frequency domain - G10L 25/84: for discriminating voice from noise - H04M 1/6058: {involving the use of a headset accessory device connected to the portable telephone} - H04R 1/1083: {Reduction of ambient noise (active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06)} - H04R 1/406: {microphones} - H04R 3/005: {for combining the signals of two or more microphones (specially adapted for hearing aids H04R25/407)} - G10L 25/78: Detection of presence or absence of voice signals (switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10) - G10L 2021/02166: {Microphone arrays; Beamforming} - H04M 2201/40: using speech recognition - H04R 1/1008: {Earpieces of the supra-aural or circum-aural type} - H04R 1/1041: {Mechanical or electronic switches, or control elements (switches in general H01H)} - H04R 1/1075: {Mountings of transducers in earphones or headphones} - H04R 2201/023: Transducers incorporated in garment, rucksacks or the like - H04R 2201/107: Monophonic and stereophonic headphones with microphone for two-way hands free communication - H04R 2410/01: Noise reduction using microphones having different directional characteristics - H04R 2420/01: Input selection or mixing for amplifiers or loudspeakers - H04R 2420/07: Applications of wireless loudspeakers or wireless microphones - H04R 2430/20: Processing of the output signals of the acoustic transducers of an array for obtaining a desired directivity characteristic (H04R2203/12 takes precedence) - H04R 2460/01: Hearing devices using active noise cancellation - G10L: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING - H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08) - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) ## Abstract A head-worn audio device is provided with a circuit for voice signal enhancement. The circuit comprises at least a plurality of microphones, arranged at predefined positions, where each microphone provides a microphone signal. The circuit further comprises a directivity pre-processor and a blind source separation processor. The directivity pre-processor is connected with the plurality of microphones to receive the microphone signals and being configured to provide at least a voice signal and a noise signal. Directivity pre-processing increases the mutual independence of the signals provided to the blind source separation processor and thus improves processing by blind source separation. The blind source separation processor receives at least the voice signal and the noise signal, and is configured to conduct blind source separation on at least the voice signal and the noise signal to provide at least an enhanced voice signal with reduced noise components. ## Claims ### Claim 1 An audio device having a circuit for voice signal enhancement, the circuit comprising at least a plurality of microphones, arranged at predefined positions, where each microphone provides a microphone signal; a directivity pre-processor, connected with the plurality of microphones to receive the microphone signals and configured to provide at least a voice signal and a noise signal; a BSS processor, connected with the directivity pre-processor to receive at least the voice signal and the noise signal, and being configured to conduct blind source separation on at least the voice signal and the noise signal to provide at least an enhanced voice signal with reduced noise components; wherein the audio device comprises microphone information of at least one of the plurality of microphones; and wherein the directivity pre-processor is configured to provide the voice signal and the noise signal from the microphone signals using the microphone information. ### Claim 2 (depends on 1) The audio device of claim 1, wherein the directivity pre-processor is configured to generate a plurality of voice candidate signals and a plurality of noise candidate signals from the microphone signals. ### Claim 3 (depends on 2) The audio device of claim 2, wherein the directivity pre-processor comprises a microphone definition database having one or more of a location and a directionality pattern of at least one of the plurality of microphones; the directivity pre-processor further comprises and a spatial directivity module to generate the plurality of voice candidate signals and the plurality of noise candidate signals. ### Claim 4 (depends on 2) The audio device of claim 2, wherein the directivity pre-processor is further configured to equalize/normalize at least one of the voice candidate signals and the noise candidate signals. ### Claim 5 (depends on 2) The audio device of claim 2, wherein the directivity pre-processor further comprises a voice candidate selection circuit, wherein the voice candidate selection circuit is configured to select one of the voice candidate signals as the voice signal and to provide the voice signal to the BSS processor. ### Claim 6 (depends on 5) The audio device of claim 5, wherein the voice candidate selection circuit is configured to determine an energy of each of the voice candidate signals and to select the voice candidate signal having the lowest energy as the voice signal. ### Claim 7 (depends on 6) The audio device of claim 6, wherein the voice candidate selection circuit is configured to determine the energy of each of the voice candidate signals in a plurality of sub-bands. ### Claim 8 (depends on 2) The audio device of claim 2, wherein the directivity pre-processor further comprises a voice filter, configured to filter voice components from each of the noise candidate signals. ### Claim 9 (depends on 8) The audio device of claim 8, wherein the voice filter is configured to receive at least one of the voice candidate signals and to filter the voice components using the received at least one voice candidate signal. ### Claim 10 (depends on 2) The audio device of claim 2, wherein the directivity pre-processor further comprises a noise candidate selection circuit, wherein the noise candidate selection circuit is configured to select one of the noise candidate signals as the noise signal and to provide the noise signal to the BSS processor. ### Claim 11 (depends on 10) The audio device of claim 10, wherein the noise candidate selection circuit is configured to determine an energy of each of the noise candidate signals and to select the noise candidate signal having the highest energy as the noise signal. ### Claim 12 (depends on 11) The audio device of claim 11, wherein the noise candidate selection circuit is configured to determine the energy of each of the noise candidate signals in a plurality of sub-bands. ### Claim 13 (depends on 1) The audio device of claim 1, wherein the BSS processor is configured to additionally provide an enhanced noise signal with reduced voice components. ### Claim 14 (depends on 1) The audio device of claim 1, wherein the audio device is formed as one of glasses, a cap, a hat, and a helmet. ### Claim 15 (depends on 1) The audio device of claim 1, wherein the audio device is a headset or a head-worn audio device. ### Claim 16 (depends on 1) The audio device of claim 1, comprising at least three microphones. ### Claim 17 (depends on 1) The audio device of claim 1, further comprising an audio output to transmit at least the enhanced voice signal to further device. ### Claim 18 A circuit for voice signal enhancement, the circuit being connectable to a plurality of microphones, where each microphone provides a microphone signal, the circuit comprising at least a directivity pre-processor, connected with the plurality of microphones to receive the microphone signals and configured to provide at least a voice signal and a noise signal; and a BSS processor, connected with the directivity pre-processor to receive at least the voice signal and the noise signal, and being configured to conduct blind source separation on at least the voice signal and the noise signal to provide at least an enhanced voice signal with reduced noise components; wherein the circuit comprises microphone information of at least one of the plurality of microphones; and wherein the directivity pre-processor is configured to provide the voice signal and the noise signal from the microphone signals using the microphone information. ### Claim 19 A method of voice signal enhancement based on a plurality of microphone signals of a plurality of microphones, the method comprising directivity pre-processing of the plurality of microphone signals to obtain at least a voice signal and a noise signal using microphone information of at least one of the plurality of microphones; and conducting blind source separation on at least the voice signal and the noise signal to obtain at least an enhanced voice signal with reduced noise components. ### Claim 20 (depends on 19) A non-transitory computer-readable medium including contents that are configured to cause a processing device to conduct the method of claim 19. ### Claim 21 A head-worn audio device having a circuit for voice signal enhancement, the circuit comprising at least a plurality of microphones, arranged at predefined positions, where each microphone provides a microphone signal; a directivity pre-processor, connected with the plurality of microphones to receive the microphone signals and configured to provide at least a voice signal and a noise signal; a BSS processor, connected with the directivity pre-processor to receive at least the voice signal and the noise signal, and being configured to conduct blind source separation on at least the voice signal and the noise signal to provide at least an enhanced voice signal with reduced noise components.