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 system and method receives one or more captured signals through a captured audio path and produces one or more playback signals through a playback audio path. The system and method executes one or more signal processing functions and measures the delays within the playback audio path and captured audio path during operation of the one or more signal processing functions. The system and method stores the measured delays in a memory and compensates the one or more signal processing functions for the playback delay and the capture delay.

A system for providing audio output. The system includes a device, e.g. a mobile phone connectable to one or more earphones. The device includes a computing platform having a processor; an audio unit configured to generate one or more output signals of arbitrary amplitude to the earphone(s); and at least one microphone configured to record the ambient power level during signal output. The user indicates his/her hearing of the output signals whereby a proportionality constant is recorded for each frequency of the output signals. The processor is configured to: analyze the proportionality constant for each frequency of one or more feedback signals from the earphone(s) to yield calibration data; adjust the amplitude or frequency based on the calibration data; generate one or more audiograms resulting from a hearing test; and adjust the device power level according to the received one or more audiograms.

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.

A fixture for calibrating an active noise canceling (ANC) earphone, the calibration fixture including an ear model and an acoustic path. The ear model is configured to support an ANC earphone and includes an ear canal extending from an outer end of the ear canal to an inner end of the ear canal. The acoustic path is external to the ear canal and extends from, at a first end of the acoustic path, the inner end of the ear canal of the ear model to an opposite, second end of the acoustic path. The acoustic path is configured to transmit a mechanical sound wave received from the inner end of the ear canal to a region external to the ear model and adjacent the outer end of the ear canal.

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 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.

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.

A method for playback of an audio signal at an individual seat-based sound (ISS) system in a coherent listening environment having a plurality of ISS systems and a plurality of listening modes. Each ISS system has a single transducer. A listening mode and a set of playback preferences are selected. A crosstalk cancellation algorithm for the ISS system of interest is generated using impulse response measurements of the audio signal, taken only in an acoustical domain, of a transfer function between the audio signal directly after the single transducer in the ISS system of interest and the audio signal at the head of the listener in the ISS system of interest. The crosstalk cancellation algorithm for the selected listening mode is applied to the audio signal, and the audio signal is played back at the single transducer of the ISS system of interest.

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.