# US 2025/0095628 A1 · Noise control apparatus, noise controlmethod, and program > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0095628 A1 - Document ID: US20250095628A1 - Status: Published application - Kind: A1 - Application number: 18/728,857 - Filed: 2022-01-21 - Published: 2025-03-20 - Earliest claimed: 2022-01-21 - Assignees: Nippon Telegraph and Telephone Corporation - Applicants: Nippon Telegraph and Telephone Corporation - Inventors: Yohei WAKISAKA; Noriyoshi KAMADO; Hiroaki ITO; Shin MURATA - Web page: https://patentgrep.com/patent/US20250095628A1 ## CPC - G10K 11/17823: {Reference signals, e.g. ambient acoustic environment} - G10K 11/178: by electro-acoustically regenerating the original acoustic waves in anti-phase - G10K 11/17817: {between the output signals and the error signals, i.e. secondary path} - G10K 11/17825: {Error signals} - G10K 11/17854: {the filter being an adaptive filter} - G10K 11/17857: {Geometric disposition, e.g. placement of microphones} - G10K 11/17881: {the reference signal being an acoustic signal, e.g. recorded with a microphone} - G10K 11/17883: {the reference signal being derived from a machine operating condition, e.g. engine RPM or vehicle speed} - G10K 2210/1282: Automobiles - G10K 2210/3026: Feedback - G10K 2210/3027: Feedforward - G10K 2210/3028: Filtering, e.g. Kalman filters or special analogue or digital filters - G10K: SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR ## Abstract To provide a noise control apparatus capable of stabilizing a noise suppression operation even when noise characteristics rapidly change in a manner that the noise control apparatus is controlled by correcting a coefficient of an adaptive filter, stopping a cancelling speaker, and the like in accordance with the current position of a vehicle such as a train. The noise control apparatus generates a cancellation signal to be reproduced by a cancelling speaker by performing an operation corresponding to position information m of a moving object in which the cancelling speaker used in active noise control is installed. ## Claims ### Claim 1 A noise control apparatus that generates a cancellation signal to be reproduced by a cancelling speaker by performing an operation corresponding to position information m of a moving object in which the cancelling speaker used in active noise control is installed. ### Claim 2 (depends on 1) The noise control apparatus according to claim 1, comprising: processing circuitry; and a noise map information storage unit that stores information indicating whether or not a position is a position at which a noise characteristic greatly changes, wherein in a determination processing the processing circuitry determines whether or not a position of the position information m is the position at which the noise characteristic greatly changes, with reference to the noise map information storage unit, and in a suppression signal generation processing the processing circuitry generates the cancellation signal for suppressing noise by using a sound collection signal of a reference microphone and a model Ma, and updates the model Ma by using the sound collection signal of an error microphone, and a different process is executed depending on whether or not the position of the position information m is the position at which the noise characteristic greatly changes. ### Claim 3 (depends on 2) The noise control apparatus according to claim 2, wherein control is performed such that the active noise control is not performed in a case where the position of the position information m is the position at which the noise characteristic greatly changes. ### Claim 4 (depends on 2) The noise control apparatus according to claim 2, wherein the noise map information storage unit stores the information indicating whether or not the position is the position at which the noise characteristic greatly changes and a model adapted to a changed noise characteristic at the position at which the noise characteristic greatly changes, and in a case where the position of the position information m is the position at which the noise characteristic greatly changes, in the determination processing the processing circuitry extracts a model Mb adapted to the changed noise characteristic corresponding to the position of the position information m from the noise map information storage unit, and changes the model Ma used in the suppression signal generation processing to the model Mb. ### Claim 5 A noise control method of generating a cancellation signal to be reproduced by a cancelling speaker by performing an operation corresponding to position information m of a moving object in which the cancelling speaker used in active noise control is installed. ### Claim 6 (depends on 5) The noise control method according to claim 5, the method, implemented by a noise control apparatus that includes processing circuitry, comprising: assuming that information indicating whether or not a position is a position at which a noise characteristic greatly changes is stored in a noise map information storage unit; a determination step in which the processing circuitry determines whether or not a position of the position information m is the position at which the noise characteristic greatly changes, with reference to the noise map information storage unit; and a suppression signal generation step in which the processing circuitry generates the cancellation signal for suppressing noise by using a sound collection signal of a reference microphone and a model Ma, and updates the model Ma by using the sound collection signal of an error microphone, wherein a different process is executed depending on whether or not the position of the position information m is the position at which the noise characteristic greatly changes. ### Claim 7 (depends on 1) A non-transitory computer-readable recording medium having recorded thereon a program for causing a computer to function as the noise control apparatus according to claim 1.