A method of equalising sound in a headset comprising an internal microphone configured to generate a first audio signal, an external microphone configured to generate a second audio signal, a speaker, and one or more processors coupled between the speaker the external microphone, and the internal microphone, the method comprising: while the headset is worn by a user: determining a first audio transfer function between the first audio signal and the second audio signal in the presence of sound at the external microphone; and determining a second audio transfer function between a speaker input signal and the first audio signal with the speaker being driven by the speaker input signal; determining an electrical transfer function of the one or more processors; determining a closed-ear transfer function based on the first audio transfer function, the second audio transfer function and the electrical transfer function; and equalising the first audio signal based on a comparison between the closed-ear transfer function and an open-ear transfer function to generate an equalised first audio signal.

An ear interface mode of headphones may be determined by measuring an acoustic response of the headphones. For example, the headphones may be determined to be in a leaky or sealed configuration. An adaptive noise cancellation (ANC) system may be controlled based on the determined ear interface mode of the headphones. For example, a set of configuration parameters may be loaded for the ANC system corresponding to the known ear interface mode. An anti-noise signal may be generated according to the selected configuration parameters, and that anti-noise signal added during playback of media, such as voice recordings, music, videos, or telephone call speech.

Disclosed herein is an acoustic system including one or more acoustically transparent loudspeakers and one or more acoustic sensors. The system can utilize the acoustic transparency of acoustically transparent loudspeakers in order to avoid echo while cancelling, creating, and modifying waves. Furthermore, the system cancels and modifies a larger system or spatially complex wave-front, not just at a singular point. The system globally senses and globally cancels sound fields in both simple and complex environments.

An integrated circuit for implementing at least a portion of a personal audio device may include an output for providing an output signal to a transducer, wherein the output signal includes a pilot signal, a microphone input for receiving a microphone signal from a microphone indicative of an output of the transducer, and a processing circuit. The processing circuit may be configured to implement a pilot signal control to apply an adjustment to the pilot signal as necessary to maintain the pilot signal at a substantially constant magnitude regardless of proximity of the transducer to a pinna and implement a proximity determination block configured to determine proximity of the transducer to the pinna based on the adjustment.

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.

An active noise cancellation method and active noise cancellation earphones are provided, which may improve a noise cancellation effect of the active noise cancellation earphones. The method includes: determining a first primary path transfer function according to a first out-of-ear data collected by the out-of-ear microphone and a first in-ear data collected by the in-ear microphone when the speaker plays audio data; determining audio data received by the in-ear microphone according to the first in-ear data, the first out-of-ear data and the first primary path transfer function; determining a first secondary path transfer function according to the audio data played through the speaker and the audio data received by the in-ear microphone; and updating an operation coefficient of the filter to a first operation coefficient according to the first primary path transfer function and/or the first secondary path transfer function.

Methods, systems, computer-readable media, devices, and apparatuses for synchronized mode transitions are presented. A first device configured to be worn at an ear includes a processor configured to, in a first contextual mode, receive a first mode change request from a second device to transition at a first time to a second contextual mode. The first mode change request is based on detection of a trigger condition. The processor is further configured to, at the first time, transition from the first contextual mode to the second contextual mode based on the first mode change request.

The present disclosure discloses an acoustic device and a method for determining a transfer function thereof. The acoustic device includes a sound production unit, a first detector, a processor, and a fixing structure. The sound production unit is configured to generate a first sound signal based on a noise reduction control signal. The first detector is configured to obtain a first residual signal including a residual noise signal formed by superposition of an environmental noise and the first sound signal at a location of the first detector. The processor is configured to estimate a second residual signal at a target spatial location that is closer to the ear canal than the first detector, and update the noise reduction control signal based on the second residual signal. The fixing structure is configured to place the acoustic device at a location near a user's ear but not blocking the ear canal.

An active noise reduction (ANR) device includes an acoustic transducer, a first sensor, and a second sensor. The acoustic transducer is configured to generate output audio. The first sensor is configured to capture audio originating from an external environment of the ANR device. The second sensor is configured to generate a signal indicative of (1) the audio originating from the external environment and (2) the output audio generated by the acoustic transducer. The output audio generated by the acoustic transducer is modified based on a portion of the signal generated by the second sensor, the portion being attributable to a resonant mode of a user's ear canal.

An audio system for an ear mountable playback device comprises a compensation filter configured to generate a third compensation signal by applying filter operations to an audio signal, and an error compensation unit configured to generate a compensated error signal on the basis of the third compensation signal and a disturbed audio signal from an error microphone. The audio system further comprises a first noise filter configured to be adapted based on the compensated error signal, and a detection unit configured to estimate the acoustic leakage condition on the basis of the first noise filter or of the disturbed audio signal and an audio output signal. The compensation filter is configured to be adapted based on the acoustic leakage condition.