A method for feedforward noise cancellation in an enclosed space within a structure is provided. The method comprises placing a microphone array inside an inner surface of the enclosed space and conducting modal testing on an outside surface of the enclosed space, wherein the modal testing comprises multiple incoherent noise sources corresponding to locations of microphones in the microphone array. Noise generated by the modal testing is processed to create a number of acoustic mathematical models of the enclosed space. In response to incoherent noise within the enclosed space, a noise canceling signal is generated according to an output of the mathematical models.

Method for automatably or automated tuning at least one operational parameter of an engine-order-cancellation (“EOC”) apparatus, the EOC apparatus being operable on the basis of a number of operational parameters, comprising the steps of: providing a defined tuning rule for automatably or automated tuning at least one operational parameter of an EOC apparatus, and automatably or automated tuning the at least one operational parameter of the EOC apparatus on basis of the provided tuning rule.

Methods for calibrating active noise-cancelling headphones, including placing the active noise-cancelling headphones on a measuring device; exciting the active noise-cancelling filter; measuring one or more relevant transmission pathways selected from x(n), m(n), and p(n) for feedforward and/or h(n) for feedback; defining at least one goal function for feedforward or feedback; calculating a complementary function for the defined goal function for at least one branch of the active noise-cancelling filter; calculating an impulse response of the complementary function from the measurements of the relevant transmission pathways; approximating operating parameters for the active noise-cancelling filter using the Prony method; and implementing the approximated operating parameters in the active noise-cancelling filter on the signal processor in order to create an approximated complementary active noise-cancelling filter, thereby calibrating the active noise-cancelling headphones.

[Problem] To provide a technology capable of comfortably enjoying audio content via multiple channels even in a noisy environment. [Solution] A wireless terminal 3 is disposed at a listening point of a multi-channel audio device 1. The multi-channel audio device 1 plays a multi-channel audio signal as audio playback signals of a plurality of channels, and outputs an audio playback signal for each channel from the corresponding speaker 2, and the wireless terminal 3 collects the environmental sound at the listening point, and transmits the sound collection signal to the multi-channel audio device 1. The multi-channel audio device 1 identifies, as a noise component, the difference between the sound collection signal received from the wireless terminal 3 and the audio playback signals of the plurality of channels output from the plurality of speakers, generates a noise canceling signal with the opposite phase to the noise component, and outputs the noise canceling signal from any speaker 2.

A method performed by a headset that includes a speaker and an in-ear microphone, the method includes performing a calibration on the headset to obtain a baseline measurement; using, while the headset is being worn by a user, an audio signal to drive the speaker that is arranged to project sound into a canal of a user's ear; capturing as a microphone signal, from the in-ear microphone of the headset, sound from within the canal of the user's ear; determining a parameter associated with the user's ear based at least on the captured microphone signal and the baseline measurement; and transmitting a notification related to one or more characteristics of one or more hearing elements of the user's ear based on the parameter.

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 simulation system and method for simulating a noise environment of a vehicle includes a memory configured to store a reference sample signal and a noise sample signal, a control unit electrically connected to the memory and configured to generate a reference signal based on the reference sample signal, generate a noise signal based on the noise sample signal, and transmit the reference signal to a noise control system, and a speaker electrically connected to the control unit and configured to convert the noise signal into a sound wave and output the sound wave.

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 sound system is provided with a headphone that includes a transducer and at least one microphone. The sound system also includes an equalization filter and a loop filter circuit. The equalization filter is adapted to equalize an audio input signal based on at least one predetermined coefficient. The loop filter circuit includes a leaky integrator circuit that is adapted to generate a filtered audio signal based on the equalized audio input signal and a feedback signal indicative of sound received by the at least one microphone, and to provide the filtered audio signal to the transducer.

A vehicle includes an engine and/or powertrain producing noise that is audible in a passenger compartment of the vehicle when the engine and/or powertrain is running. An active noise control arrangement includes a first loudspeaker disposed within a passenger compartment of the vehicle. A digital signal processor receives audio data and transmits an audio signal to the first loudspeaker dependent upon the audio data. A microphone is disposed within the passenger compartment and converts the sound from the first loudspeaker and the noise within the passenger compartment into a microphone signal. The microphone signal is transmitted to the digital signal processor, and the digital signal processor modifies the audio signal such that the audio signal attenuates the noise in the passenger compartment. A vehicle processor transmits a simulated noise signal to a second loudspeaker for use in testing effectiveness of the active noise control arrangement in attenuating noise when the engine and/or powertrain is not running and not producing noise.