# US 2008/0189107 A1 · Estimating own-voice activity in a hearing-instrument system from direct-to-reverberant ratio > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0189107 A1 - Document ID: US20080189107A1 - Status: Published application - Kind: A1 - Application number: 11/878,275 - Filed: 2007-07-23 - Published: 2008-08-07 - Earliest claimed: 2007-02-06 - Assignees: Oticon A/S - Inventors: Soren Laugesen - Web page: https://patentgrep.com/patent/US20080189107A1 ## CPC - G10L 21/02: Speech enhancement, e.g. noise reduction or echo cancellation (reducing echo effects in line transmission systems H04B3/20; echo suppression in hands-free telephones H04M9/08) - G10L 25/51: for comparison or discrimination - G10L 21/00: Speech or voice signal processing techniques to produce another audible or non-audible signal, e.g. visual or tactile, in order to modify its quality or its intelligibility (G10L19/00 takes precedence) - G10L 21/06: Transformation of speech into a non-audible representation, e.g. speech visualisation or speech processing for tactile aids (G10L15/26 takes precedence) - G10L 2021/02087: {the noise being separate speech, e.g. cocktail party} - G10L 2021/065: {Aids for the handicapped in understanding} - H04R 25/505: {using digital signal processing} - G10L: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING - 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 method of identifying the user's own voice in a hearing instrument system and a hearing instrument system for performing such method is provided wherein a direct-to-reverberant ratio (DtoR) between the signal energy of a direct sound part (1a; 1b) and that of a reverberant sound part (2a, 3a; 2b, 3b) of at least a part of a recorded sound is used to assess wether the sound originates from the users own voice or not. This allows a very reliable detection of the users own voice in a hearing-instrument system. Further, a hearing-instrument system comprising an own-voice detector configured to perform such method is provided. ## Claims ### Claim 1 Method of identifying the user's own voice in a hearing-instrument system (20), characterized by the steps: determining a direct-to-reverberant ratio (DtoR) between the signal energy of a direct sound part and that of a reverberant sound part of at least a part of a recorded sound; and assessing whether the sound originates from the user's own voice on the basis of the direct-to-reverberant ratio. ### Claim 2 (depends on 1) Method in accordance with claim 1 characterized in that the step of assessing whether the sound originates from the user's own voice includes the steps of: comparing the direct-to-reverberant ratio to an own-voice threshold value and assessing that the recorded sound originates from the user's own voice if the direct-to-reverberant ratio is above the own-voice threshold value. ### Claim 3 (depends on 1) Method in accordance with claim 1 characterized in that the method further comprises the step of partitioning the recorded sound into a number of frequency bands; the direct-to-reverberant ratio between the signal energy of the direct sound part and that of the reverberant sound part is determined for each of the number of frequency bands; and it is assessed whether the recorded sound originates from the user's own voice on the basis of the direct-to-reverberant ratios of the number of frequency band. ### Claim 4 (depends on 3) Method in accordance with claim 3 characterized in that the step of assessing whether the sound originates from the user's voice includes the following steps: combining the direct-to-reverberant ratios determined for each of the number of frequency bands to obtain a combined direct-to-reverberant ratio; comparing the combined direct-to-reverberant ratio to an own-voice threshold value; and assessing that the recorded sound originates from the user's own voice if the combined direct-to-reverberant ratio is above an own-voice threshold. ### Claim 5 (depends on 1, 2, 3, 4) Method in accordance with one of claims 1 to 4 characterized in that determining the direct-to-reverberant ratio (DtoR) includes the following steps: determining the sound signal energy in short time intervals to obtain the envelope of the signal energy in these intervals; calculating the direct-to-reverberant ratio from the envelope of the signal energy in these intervals. ### Claim 6 (depends on 1) Method in accordance with claim 1 characterized in that assessing that the sound originates from the user's own voice is based on a combination of the direct-to-reverberant ratio (DtoR) and another characteristic of the recorded sound. ### Claim 7 (depends on 1) Method in accordance with claim 1 characterised in that the method further comprises the step of identifying a sound event in the recorded sound that allows a reliable estimation of the direct-to-reverberant ratio (DtoR). ### Claim 8 Hearing-instrument system comprising an own voice detector characterized in that the own voice detector includes: determining means for determining a direct-to-reverberant ratio (DtoR) between the signal energy of a direct sound part and that of a reverberant sound part of at least a part of a recorded sound; and assessing means for assessing whether the recorded sound originates from the user's own voice on the basis of the direct-to-reverberant ratio (DtoR). ### Claim 9 (depends on 8) Hearing-instrument system in accordance with claim 8 characterized in that the assessing means are configured to compare the direct-to-reverberant ratio (DtoR) with an own-voice threshold value and to assess that the recorded sound originates from the user's own voice if the direct-to-reverberant ratio (DtoR) is above the own-voice threshold value. ### Claim 10 (depends on 8) Hearing-instrument system in accordance with claim 8 characterized in that the hearing-instrument system further comprises partitioning means for separating the sound event into different frequency bands; the determining means determines the direct-to-reverberant ratio (DtoR) in each frequency band; and the assessing means assesses whether the recorded sound event originates from the user's own voice on the basis of the direct-to-reverberant ratios in each frequency band. ### Claim 11 (depends on 10) Hearing-instrument system in accordance with claim 10 characterized in that the assessing means are configured for combining the direct-to-reverberant ratios (DtoR) determined for each of the number of frequency bands to obtain a combined direct-to-reverberant ratio (DtoR), comparing the combined direct-to-reverberant ratio (DtoR) to an own-voice threshold value; and assessing that the recorded sound originates from the user's own voice if the combined direct-to-reverberant ratio (DtoR) is above an own-voice threshold. ### Claim 12 (depends on 8, 9, 10, 11) Hearing-instrument system in accordance with one of claims 8 to 11 characterized by combining means combining the output of the assessing means with the output of other own-voice detectors to obtain a more robust decision about whether the recorded sound originates from the user's own voice or not. ### Claim 13 (depends on 8) Hearing-instrument system in accordance with claim 8 characterized in that the determining means is configured for determining the sound signal energy in short time intervals to obtain envelope of the signal energy in these intervals and for calculating the direct-to-reverberant ratio (DtoR) from the envelope of the signal energy in these intervals. ### Claim 14 (depends on 7) Hearing-instrument system in accordance with claim 7 characterized by further comprising identification means for identifying a sound event in the recorded sound that allows a reliable estimation of the direct-to-reverberant ratio (DtoR).