Apple Inc.

Martin Kuster

Tom-Davy W Saux

Victoria Chiu

Ethan Larry Huwe

Arun Dhyaneshwar Chawan

Scott Charles Grinker

Lee M Panecki

Brian R Twehues

Yuta Kuboyama

Hanchi Chen

Michael B Minerbi

Sean J Docherty

Eric X Zhou

Prateek Murgai

Julia C Canning

Haochuan Sang

Kyle Tse

Ryan M Buck

Pengchuan Wang

Sean T Bong

Disclosed are systems and methods for adaptive noise cancellation (ANC) at a virtual microphone located at the eardrum of a wearer of an earphone. The techniques estimate the level of leakiness of ambient noise in the earphone from the magnitude of the gain of the transfer function of the feed forward loop filter of the ANC. Based on the estimated leakiness, the techniques estimate the transfer function of the feed forward loop filter to compensate for the difference in the effect of noise cancellation at the virtual microphone and error microphone. A bias term that represents the difference in the frequency response of the attenuated noise at the virtual and error microphone may be added to the adaptive feed forward algorithm. The ANC operation may apply the bias term to the adaptive feed forward loop filter to reduce the ambient noise at the eardrum rather than at the error microphone.

Adaptive virtual microphone for earbuds

Disclosed are systems and methods for performing adaptive equalization operations to reduce variations in the frequency response of audio signals at the eardrum of a wearer of an earphone. The assumption that the frequency response of the error microphone matches the frequency response at the eardrum may not be true due to signal leakage effects and the shape of the ear canal. Techniques are disclosed for the adaptive equalization operations to perform a calibration algorithm to compensate for the effects of the signal leakage and the shape of the ear canal. The earphone may estimate the transfer function from the speaker to the error microphone and may estimate the load impedance from the earphone based on a calibrated relationship between the transfer function and the load impedance. The adaptive equalization may use a calibration algorithm to adjust the frequency response at the error microphone to match that at the eardrum.

Adaptive equalization compensation for earbuds

A portable acoustic device comprising: a device housing that defines an internal cavity, the device housing comprising a speaker housing portion and a stem portion extending away from the speaker housing portion; a first acoustic port formed through a wall of the speaker housing; an audio driver disposed within the speaker housing portion and aligned to emit sound through the acoustic first port; a battery disposed within the speaker housing portion and positioned an opposite side of the audio driver than the acoustic port; an antenna disposed in the stem; a user input region disposed along the stem; and a system in a chip disposed in the stem, the system in a chip comprising: a processor that controls operation of the portable wireless acoustic device, charging circuitry, an accelerometer, a wireless communication controller, support components for the antenna and support components for the user input region.

Wireless listening device

Processing sound received by a device can include receiving a first signal from a first microphone of the device and a second signal from a second microphone of the device, where the first and second microphones capture sounds from a sound field. A ratio between the acoustic pressure and the particle velocity of the sound field can be calculated. In response to the ratio exceeding a threshold, speech signal processing is performed on one or more of the microphone signals. Other aspects are also described and claimed.

User voice detection based on acoustic near field

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Saratoga, CA, United States of America

Martin Kuster