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.

The disclosure is related to a calibration system for active noise cancellation and a speaker apparatus. The calibration system receives the signals with feedforward control or feedback control active noise cancellation. A gain adjustment element is used to adjust a gain of the signals, and a path selection switch is used to switch connection to a first operational amplifier or to a second operational amplifier. In addition to driving signals, the operational amplifier is also used to adjust a phase of the output signals. The calibration system is able to balance the gain of the signals with active noise cancellation and adjust the phase of signals of a left-channel circuit and a right-channel circuit through gain-phase adjustment. The related speaker apparatus is such as an earphone with the feedforward ANC control circuit, the feedback ANC control circuit, or a hybrid ANC circuit.

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 vehicle includes a suspension system, a sensor for measuring a vibration signal produced from the suspension system, and a microphone for measuring a noise signal in an interior of the vehicle caused by the vibration signal, wherein the sensor is installed at an interior sensor position determined based on an analysis of a level of contribution of the vibration signal to the noise signal, from among candidate sensor positions in the interior of the vehicle.

The embodiments of the disclosure provide a method for adjusting a noise cancellation mode, an electronic device, and a computer readable storage medium. The method includes: estimating a noise perception indicator corresponding to an environmental noise; and adjusting a noise cancellation mode of an wearable audio device according to the noise perception indicator.

In a method for tuning at least one parameter of a noise cancellation enabled audio system with an ear mountable playback device comprising a speaker and a feedforward microphone the playback device is placed onto a measurement fixture, the speaker facing a test microphone located within an ear canal representation. The parameter is varied between a plurality of settings while a test sound is played. A measurement signal from the test microphone is received and stored in the audio system at least while the parameter is varied. A power minimum in the stored measurement signal and a tune parameter associated with the power minimum are determined in the audio system from the plurality of settings of the varied parameter.

Active noise reduction (ANR) headphones and associated methods are provided. The ANR headphones may include a memory to store a plurality of profiles each including controller information and acoustic parameters in addition to a profile selection routine executable by a processor of the ANR headphone. The profile selection routine may be configured to identify acoustic characteristics of a subject wearing the ANR headphone, compare the acoustic characteristics of the subject with the acoustic parameters of the plurality of profiles, select a profile from the plurality of profiles based on the comparison between the acoustic characteristics of the subject with the acoustic parameters of the selected profile, and provide the controller information of the selected profile to a noise reduction circuit of the ANR headphone.

A method of calibrating an earphone may include: securing an ANC earphone to a calibration fixture, the calibration fixture including an ear model configured to support the ANC earphone, the ear model having an ear canal configured to anatomically resemble a human ear canal and a concha configured to anatomically resemble a human ear concha, the ear canal extending from the concha to an inner end of the ear canal; generating, with the ANC earphone, an audio signal based on a reference tone; determining a characteristic of the audio signal; comparing the characteristic of the audio signal to a previously determined reference characteristic; and adjusting a gain value of the ANC earphone based on the comparing. Additional methods and apparatus are also disclosed.

A method of operating an audio system in a vehicle includes providing m number of microphones disposed within a passenger compartment of the vehicle. The microphones produce a plurality of microphone signals. Within the passenger compartment of the vehicle, k number of loudspeakers are provided. A plurality of convergence factors for use in performing active noise control are estimated. The estimating includes calculating an Eigen value () of an autocorrelation matrix of a passenger compartment transfer function as ${}_k\left(\right)=\frac{{A_k\left(\right)}^2}{2},$
wherein A.sub.k() is the frequency response of the passenger compartment transfer function. A frequency .sub.min of a local minimum of () is determined. A largest stable value for Max(.sub.min) is found by experimentation, wherein a rotational speed of an engine of the vehicle, expressed in revolutions per minute, f.sub.rpm=2.sub.min. A calibration factor is calculated as L=(.sub.min)Max(.sub.min). All values of Max() are estimated as $\mathrm{Max}\left(\right)=\frac{L}{\left(\right)}.$
A plurality of active noise controlled audio signals are transmitted to the loudspeaker. The active noise controlled audio signals are dependent upon the microphone signals and the estimated convergence factors.

Active noise reduction (ANR) headphones and associated methods are provided. The ANR headphones may include a memory to store a plurality of profiles each including controller information and acoustic parameters in addition to a profile selection routine executable by a processor of the ANR headphone. The profile selection routine may be configured to identify acoustic characteristics of a subject wearing the ANR headphone, compare the acoustic characteristics of the subject with the acoustic parameters of the plurality of profiles, select a profile from the plurality of profiles based on the comparison between the acoustic characteristics of the subject with the acoustic parameters of the selected profile, and provide the controller information of the selected profile to a noise reduction circuit of the ANR headphone.