An adaptive filter calculates frequency domain coefficients and in the frequency domain dynamically adjusts a leakage/step size parameter that controls adaptation of the adaptive filter based on the calculated frequency domain coefficients (e.g., based on a peak magnitude of the coefficients among frequency bins or on the magnitude of the coefficient of the corresponding frequency bin). The adaptive filter calculates the coefficients based on frequency domain input and error signals, dynamically adjusts a frequency domain coefficient magnitude limit parameter based on the calculated frequency domain coefficients (e.g., approximately proportionally to a peak magnitude of the coefficients among frequency bins) and uses the dynamically adjusted frequency domain coefficient magnitude limit parameter to limit a magnitude of the calculated frequency domain coefficients. The limit may be engaged above a frequency bin based on the peak magnitude frequency bin. An ANC system may employ the filter.

An active noise reduction device includes a standard signal generator, an adaptive filter unit, a control sound output unit, and an error signal detector. The adaptive filter unit includes a control signal generator, a filter coefficient update unit, and a step size setting unit. The control signal generator multiplies a standard signal by a filter coefficient to generate a control signal. Based on a reference signal and an error signal, the filter coefficient update unit updates the filter coefficient so as to minimize the error signal. The step size determiner sets a step size parameter indicating an update amount of the filter coefficient. The filter coefficient update unit sets a step size adjustment coefficient for adjusting the step size parameter based on an audio information feature amount and a change of the control signal.

An audio playback device having a noise-cancelling mechanism is provided that includes an external sound-receiving circuit that receives external noise, a fixed-coefficient filtering circuit, an operation circuit, an audio playback circuit, an internal sound-receiving circuit and an adjusting circuit. The fixed-coefficient filtering circuit generates an inverted signal including a main and an auxiliary inverted components having the same amplitude and phases orthogonal to each other according to the external noise. The operation circuit multiplies the inverted signal by adjusting parameters to generate an adjusted inverted signal. The audio playback circuit receives and playbacks an audio signal and the adjusted inverted signal to generate a playback result. The internal sound-receiving circuit receives the playback result to generate a received sound signal. The adjusting circuit generates the adjusting parameters according to an error signal between the received sound signal and the audio signal and the inverted signal.

Various implementations include audio devices and related computer-implemented methods for controlling playback of augmented reality (AR) audio. Certain implementations include approaches for initiating AR audio playback at an audio device independent of a detected geographic location of the device. Additional implementations include approaches for initiating AR audio playback based upon one or more geographic location-specific indicators for the device.

A hearing protection headset that can be worn by a user includes left and right earcups. The headset includes a radio communication system enabling at least one radio signal to be received and played through one or both of the earcups. Noise control circuitry in the headset is configurable by a user between at least three active modes of operationthe circuitry having a first active mode in which the headset provides automatic noise reduction, a second active mode in which the headset provides automatic noise cancellation, and a third active mode in which the headset provides both automatic noise reduction and automatic noise cancellation. A switch is manually operable by the user to configure the circuitry between the first active mode and the second active mode and the third active mode.

Systems, methods, and computer-readable media are disclosed for acoustic control of a vehicle's interior. Example methods may include detecting environmental sounds external to a cabin of a vehicle and determining at least one first sound from the environmental sounds, wherein the cabin is configured to reduce a volume of the environmental sounds below a threshold; determining location information comprising a direction and a distance of the first sound with respect to the vehicle; and generating a second sound based on the first sound and the location information that reproduces a spectral feature of the first sound.

A headphone device includes a speaker housing, a first feedforward microphone, and a second feedforward microphone. The first feedforward microphone is coupled to the speaker housing at a first location, and the second feedforward microphone is coupled to the speaker housing at a second location. The headphone device also includes an active noise cancelling (ANC) circuit configured to generate an anti-noise signal based on at least one of a first signal from the first feedforward microphone and a second signal from the second feedforward microphone. The headphone device also includes a speaker configured to generate an audio output at least partially based on the anti-noise signal.

Aspects of the present disclosure provide methods, apparatuses, and systems for a personalized wake-up system. A sleep assistance device outputs a sound. In response to detecting a sound that exhibits one or more predetermined sound properties, actions are taken to adjusting the sound in an effort to wake the subject. Examples of predetermined sound properties include any sound detected over a threshold decibel level, sounds detected at a certain frequency spectrum. According to aspects, subject may further configure the system to alert the subject based on a set of personalized sounds the subjects considers to be important. According to aspects, the audio device or system is configured to determine the subject is awake based on collected biosignal parameters. The audio device or system takes further actions to disrupt the subject's sleep until the subject is determined to be awake.

The problem to be solved is to improve a noise cancelling function. A detection microphone, a speaker, and a housing are included. The detection microphone detects noise and has an input vibrating plate. The speaker has an output vibrating plate. The housing accommodates at least the speaker and the detection microphone therein. The input vibrating plate and the output vibrating plate are disposed approximately in the same orientation. This ensures that a sound is output from the speaker while a sound is input to the detection microphone with the input vibrating plate and the output vibrating plate facing each other, thus making it possible to bring the input vibrating plate and the output vibrating plate closer to each other. As a result, it is less likely for a phase lag to take place between the sound output from the speaker and the sound input to the detection microphone, thus providing higher noise detection accuracy of the detection microphone and contributing to an improved noise cancelling function.

A personalized earphone for people with auditory abnormality, includes a microphone, a preamplifier, an analogue-to-digital (A/D) converter, a Bluetooth wireless circuit, a Digital Signal Processing (DSP) module, a digital-to-analogue (D/A) converter, a post-amplifier and a loudspeaker. The microphone is arranged to pick up an ambient noise and deliver information about the ambient noise to the preamplifier, the preamplifier is arranged to convert the ambient noise to a digital signal and input the digital signal to the DSP module. The DSP module is arranged to internally generate a noise-reduction signal that is converted to an original noise, and convert the noise-reduction signal to an analogue signal that is amplified by the post-amplifier and delivered to the loudspeaker. The DSP module is connected with the Bluetooth wireless circuit.