A device can include a microphone, a memory configured to store a sound source table including correspondence relationships among boarding items, virtual sound items and filter set values, and a processor configured to receive a sound signal through the microphone and determine a first filter set value matching characteristics of the received sound signal using the sound source table.

A sound control device mounted in a vehicle and control method thereof includes obtaining whether an audio function is ON or OFF, and determining a maximum limit value for a displacement of a speaker due to a noise control signal according to whether the audio function is ON or OFF.

The headphones (10) comprise: a transducer (16) (12); an noise-canceling processing chain (30, 40) comprising: a microphone (31, 41); a noise-canceling processing filter (34, 44) which comprises in series: a stabilisation filter (34A, 44A) whose transfer function is substantially equal to the inverse of the transfer function of the processed secondary path, and a noise cancellation filter (34B, 44B) whose transfer function is a noise cancellation transfer function. The secondary path is formed between the transducer (16) and the eardrum, and the transfer function of the processed secondary path is the transfer function of the secondary path combined with the transfer functions of the processing components, excluding the processing filter (34, 44).

Disclosed embodiments may relate to systems and methods for monitoring and/or mapping noise data from a plurality of noise monitoring devices. In some embodiments, the plurality of noise monitoring devices may include hearing protection devices configured to detect noise, and typically may communicate such noise data (which may also include location) so that the noise data can be pooled. The pooled noise data from the plurality of noise monitoring devices may then be used to the benefit of one or more of such noise monitoring devices.

According to one embodiment, a noise reduction system for reducing noise including impact noise repetitively generated at a time interval includes the following elements. The error signal generator generates an error signal based on the noise being detected. The delay signal generator has a time delay characteristic and delays a signal, which is generated based on the error signal, to generate a delay signal, the time delay characteristic being determined based on an imaging sequence or pre-scanning by the MRI device and corresponding to the time interval. The control filter generates the first control signal from the delay signal. The loudspeaker unit includes at least one pair of a first filter and a control loudspeaker and a transmission unit.

An apparatus on a vehicle comprises one or more sensors, one or more nozzles that output fluid to clean the respective one or more sensors, and a compressor that generates fluid such as compressed air. The compressor is in fluid communication with the one or more nozzles. The apparatus further comprises one or more processors, and a memory storing instructions that, when executed by the one or more processors, cause the system to determine information of an acoustic emission from the compressor and to counteract the acoustic emission based on the determined information.

A method may include adaptively generating an anti-noise signal for countering the effects of ambient audio sounds at an acoustic output of the transducer by adapting a response of an adaptive filter that filters a reference microphone signal in conformity with an error microphone signal and the reference microphone signal to minimize the ambient audio sounds in the error microphone, generating a scaled anti-noise signal by applying a scaling factor to the anti-noise signal, further adjusting the response of the adaptive filter independent of a source audio signal by altering an input to the coefficient control block of the adaptive filter to compensate for the scaling factor, and combining the scaled anti-noise signal with the source audio signal to generate an audio signal provided to the transducer.

A method for tuning filter parameters of a noise cancellation enabled audio system with an ear-mountable playback device comprising a speaker and a feedback noise microphone located in proximity to the speaker comprises provision of acoustic transfer functions between the speaker and the feedback noise microphone, between the speaker and an eardrum, between an ambient sound source and the eardrum and between the ambient sound source and the feedback noise microphone. The parameters of a feedback filter function, which is designed to process a feedback noise signal, are tuned. A noise cancellation performance of the audio system at the eardrum is determined based on each of the acoustic transfer functions and on the feedback filter function.

Audio systems, methods, and computer readable mediums having program code to receive a harmonic signal related to rotating equipment, such as a vehicle drivetrain in some examples, and provide a harmonic cancellation (or enhancement) signal. The harmonic cancellation signal is transduced into an acoustic signal, and a feedback sensor, such as a microphone, detects an error signal representative of acoustic energy at a first location in the environment. A projection filter filters the error signal to provide an estimated error signal at a second location in the environment, such as at the location of an occupant's ear(s). An adaptive module adjusts the cancellation signal based on the estimated error signal.

Disclosed embodiments may relate to systems and methods for monitoring and/or mapping noise data from a plurality of noise monitoring devices. In some embodiments, the plurality of noise monitoring devices may include hearing protection devices configured to detect noise, and typically may communicate such noise data (which may also include location) so that the noise data can be pooled. The pooled noise data from the plurality of noise monitoring devices may then be used to the benefit of one or more of such noise monitoring devices.