A method of calibrating a feedback-based noise cancellation system of an ear device may involve obtaining a measured plant response of the ear device, obtaining a reference plant response value and determining a plant response variation between the reference plant response value and a value corresponding to the measured plant response. The method may involve obtaining a measured a coupler response of the ear device, obtaining a reference coupler response value and determining a coupler response variation between the reference coupler response value and a value corresponding to the measured coupler response. The method may involve determining, based at least in part on the plant response variation and the coupler response variation, a microphone signal gain correction factor and applying the microphone signal gain correction factor to ear device microphone signals that are input to a feedback loop of the feedback-based noise cancellation system.

A first input signal captured by one or more sensors associated with an ANR headphone is received. A frequency domain representation of the first input signal is computed for a set of discrete frequencies, based on which a set of parameters is generated for a digital filter disposed in an ANR signal flow path of the ANR headphone, the set of parameters being such that a loop gain of the ANR signal flow path substantially matches a target loop gain. Generating the set of parameters comprises: adjusting a response of the digital filter at frequencies (e.g., spanning between 200 Hz-5 kHz). A response of at least 3 second order sections of the digital filter is adjusted. A second input signal in the ANR signal flow path is processed using the generated set of parameters to generate an output signal for driving the electroacoustic transducer of the ANR headphone.

A method of calibrating a feedback-based noise cancellation system of an ear device may involve obtaining a measured plant response of the ear device, obtaining a reference plant response value and determining a plant response variation between the reference plant response value and a value corresponding to the measured plant response. The method may involve obtaining a measured a coupler response of the ear device, obtaining a reference coupler response value and determining a coupler response variation between the reference coupler response value and a value corresponding to the measured coupler response. The method may involve determining, based at least in part on the plant response variation and the coupler response variation, a microphone signal gain correction factor and applying the microphone signal gain correction factor to ear device microphone signals that are input to a feedback loop of the feedback-based noise cancellation system.

An active noise cancellation system includes a sensor operable to sense environmental noise and generate a corresponding reference signal, a fixed noise cancellation filter including a predetermined model of the active noise cancellation system operable to generate an anti-noise signal, and a tunable noise cancellation filter operable to modify the anti-noise signal in accordance with stored coefficients, wherein the tunable noise cancellation filter is further operable to modify the stored coefficients in real-time based on user feedback and generate a tuned anti-noise signal that models tunable deviations from the predetermined noise model. A graphical user interface is operable to receive user adjustments of tunable parameters in real-time, the tunable parameters corresponding to at least one of the stored coefficients.

A system and a method for evaluating noise cancelling capability are provided, and the system and method are configured to evaluate a noise cancelling capability of an external device. The system includes a mixer, a player, a recorder and a comparator. The mixer receives and mixes a target audio file and a noise audio file and outputs a mix audio file. The player is connected to the mixer for receiving the mix audio file. The player outputs a first audio signal to the external device. The external device cancels the noise of the first audio signal and outputs a second audio signal. The recorder receives the second audio signal and outputs a noise-cancelled audio file. The comparator is connected to the recorder for receiving the noise-cancelled audio file. The comparator compares the noise-cancelled audio file and the target audio file and outputs an evaluation report according to a comparing result.

A first input signal captured by one or more sensors associated with an ANR headphone is received. A frequency domain representation of the first input signal is computed for a set of discrete frequencies, based on which a set of parameters is generated for a digital filter disposed in an ANR signal flow path of the ANR headphone, the set of parameters being such that a loop gain of the ANR signal flow path substantially matches a target loop gain. Generating the set of parameters comprises: adjusting a response of the digital filter at frequencies (e.g., spanning between 200 Hz-5 kHz). A response of at least 3 second order sections of the digital filter is adjusted. A second input signal in the ANR signal flow path is processed using the generated set of parameters to generate an output signal for driving the electroacoustic transducer of the ANR headphone.

A method for calibrating an ANC-enabled portable audio device having microphones plays continuously a calibration sound by a calibrated speaker of a test station separate from the device. For each microphone of all the microphones, a microphone calibration value is computed using a comparison of a predetermined level and a measured level of an audio signal transduced by the microphone in response to the continuously-played calibration sound. The calibration is done without using a microphone of the test station. A processing element of the device may be programmed to make the comparison and computation. The processing element also causes a speaker of the device to generate a second calibration sound, measures a second level while the computed calibration value is applied to one of microphones (e.g., error microphone), and computes a calibration value for the device speaker using a comparison of a predetermined level and the second level.

A system for evaluating a noise management module of a vehicle includes a controller programmed to filter speaker signals from the noise management module using an auralization model to produce auralized sound signals that create a spatial effect to simulate sound in the vehicle at a predetermined position within the vehicle that is different than the positions corresponding to microphones used by the noise management module.

Provided is an active noise cancellation (ANC) method applied for an ANC headphone. The ANC method includes: in a channel estimation mode, estimating a plurality of environment channels by generating, transmitting and capturing a training signal; in the channel estimation mode, tuning a plurality of ANC filters based on the estimated plurality of environment channels; and in a normal mode, performing ANC on an input signal based on the plurality of ANC filters.

In at least one embodiment, a computer-program product embodied in a non-transitory computer readable medium that is programmed to perform selective active noise cancellation (ANC) for a vehicle is provided. The computer-program product comprising instructions to determine an amount of noise present in a first zone and a second zone and to selectively drive only at least one first loudspeaker in the first zone to generate a first cancellation field to cancel road noise and/or engine noise if the amount of noise in the first zone is greater than the amount of noise in the second zone. The computer-program product comprising instructions to selectively drive only at least one second loudspeaker in the second zone to generate the second cancellation field to cancel road noise and/or engine noise if the amount of noise in the second zone is greater than the amount of noise in the first zone.