# US 2010/0166198 A1 · Hearing Instrument with Improved Initialisation of Parameters of Digital Feedback Suppression Circuitry > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0166198 A1 - Document ID: US20100166198A1 - Status: Published application - Kind: A1 - Application number: 12/389,297 - Filed: 2009-02-19 - Published: 2010-07-01 - Earliest claimed: 2008-12-30 - Assignees: GN ReSound A/S - Inventors: Shawn PERMAN - Web page: https://patentgrep.com/patent/US20100166198A1 ## CPC - H04R 25/453: {electronically} - H04R 25/70: {Adaptation of deaf aid to hearing loss, e.g. initial electronic fitting} - 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 modelling a feedback path from a receiver to a microphone in a hearing instrument, includes applying an electronic probe signal with an increasing level as a function of time to the receiver for conversion of the electronic probe signal into an acoustic probe signal output by the receiver, monitoring values of a first quality parameter calculated based at least in part on recorded microphone output signal, and after the first quality parameter reaches a predetermined first threshold value, determining at least one parameter of the feedback path based at least in part on the recorded microphone output signal values. ## Claims ### Claim 1 A method of modelling a feedback path from a receiver to a microphone in a hearing instrument, comprising: applying an electronic probe signal with an increasing level as a function of time to the receiver for conversion of the electronic probe signal into an acoustic probe signal output by the receiver, monitoring values of a first quality parameter calculated based at least in part on recorded microphone output signal, and after the first quality parameter reaches a predetermined first threshold value, determining at least one parameter of the feedback path based at least in part on the recorded microphone output signal values. ### Claim 2 (depends on 1) The method according to claim 1, wherein the act of applying the electronic probe signal comprises: refraining from further increasing the level of the probe signal when the first quality parameter has reached the predetermined first threshold value. ### Claim 3 (depends on 1) The method according to claim 1, further comprising: monitoring values of a second quality parameter calculated based at least in part on the recorded microphone output signal, and terminating the application of the probe signal to the receiver when the second quality parameter has reached a predetermined second threshold value. ### Claim 4 (depends on 3) The method according to claim 3, wherein the first quality parameter and the second quality parameter are identical. ### Claim 5 (depends on 3) The method according to claim 3, further comprising estimating an impulse response of the feedback path, wherein the second quality parameter is a parameter of the impulse response. ### Claim 6 (depends on 3) The method according to claim 3, wherein at least one of the first quality parameter and the second quality parameter is a function of the output signal of the microphone of the hearing instrument. ### Claim 7 (depends on 1) The method according to claim 1, further comprising estimating an impulse response of the feedback path. ### Claim 8 (depends on 7) The method according to claim 7, wherein the first quality parameter is a parameter of the impulse response. ### Claim 9 (depends on 8) The method according to claim 8, wherein the parameter of the impulse response is selected from the group consisting of a peak-to-peak ratio of head and tail parts of the impulse response, a noise-to-noise ratio of head and tail parts of the impulse response, and a peak to signal-to-noise ratio of the impulse response. ### Claim 10 A hearing instrument comprising: a microphone for converting incoming sound into a microphone audio signal; a Digital Feedback Suppression Circuit for modelling a feedback path of the hearing instrument; a signal processor for processing the audio signal; a receiver connected to an output of the signal processor for converting the processed audio signal into a sound signal; and a probe signal generator controlled by the signal processor for providing a probe signal to the receiver, wherein the receiver is configured for converting the probe signal into an acoustic probe signal output; wherein the signal processor is configured for (1) recording the microphone audio signal, (2) controlling the probe signal generator for increasing a level of the probe signal, (3) monitoring values of a first quality parameter calculated based at least in part on the recorded audio signal; and (4) determining at least one parameter of the feedback path based at least in part on the recorded audio signal after the first quality parameter has reached a predetermined first threshold value. ### Claim 11 (depends on 10) The hearing instrument according to claim 10, wherein the signal processor is further configured for controlling the probe signal generator for refraining from further increasing the level of the probe signal when the first quality parameter has reached the predetermined first threshold value. ### Claim 12 (depends on 10) The hearing instrument according to claim 10, wherein the signal processor is further configured for: monitoring values of a second quality parameter calculated based at least in part on the recorded microphone output signal, and terminating the providing of the probe signal to the receiver when the determined second quality parameter has reached a predetermined second threshold value. ### Claim 13 (depends on 12) The hearing instrument according to claim 12, wherein the signal processor is further configured for estimating an impulse response of the feedback path, and wherein the second quality parameter is a parameter of the impulse response. ### Claim 14 (depends on 12) The hearing instrument according to claim 12, wherein the first quality parameter and the second quality parameter are identical. ### Claim 15 (depends on 10) The hearing instrument according to claim 10, wherein the signal processor is further configured for estimating an impulse response of the feedback path. ### Claim 16 (depends on 15) The hearing instrument according to claim 15, wherein the first quality parameter is a parameter of the impulse response. ### Claim 17 (depends on 16) The hearing instrument according to claim 16, wherein the parameter of the impulse response is selected from the group consisting of the a peak-to-Peak Ratio of head and tail parts of the impulse response, a noise-to-noise Ratio of head and tail parts of the impulse response, and a peak to signal-to-noise ratio of the impulse response.