Ultrasound mitigation in wearable devices
AssigneeApple Inc.
InventorsHanchi Chen, Jianjun He, Vladan Bajic
Life of this patent
Estimating the term…
Abstract
A wearable device may include a microphone configured to generate a microphone signal, a speaker configured to be driven by an audio signal, and one or more processors configured to process the microphone signal to determine an amount of ultrasound in the microphone signal; determine, based on the amount of ultrasound, a parameter to control a digital filter that attenuates energy in the microphone signal, in which the digital filter attenuates more when the amount of ultrasound is increasing and less when the amount of ultrasound is decreasing; and apply the digital filter to the microphone signal to generate a reference audio signal that is then processed in a path that produces the audio signal to drive the speaker.
Claims20
A wearable device, comprising:
- a microphone configured to generate a microphone signal;
- a speaker configured to be driven by an audio signal;
- and
- one or more processors configured to:
- determine an amount of ultrasound in the microphone signal;
- dynamically apply a digital filter to the microphone signal to generate a reference audio signal, wherein the digital filter attenuates more energy in the microphone signal when the amount of ultrasound is increasing and attenuates less energy in the microphone signal when the amount of ultrasound is decreasing;
- and
- drive the speaker using the reference audio signal, wherein a path to the speaker includes at least one of a feedforward filter of an acoustic noise cancellation (ANC) subsystem or a transparency filter of a transparency subsystem.
A method, comprising:
- determining an amount of ultrasound in a microphone signal;
- dynamically applying a digital filter to the microphone signal to generate a reference audio signal, wherein the digital filter attenuates more energy in the microphone signal when the amount of ultrasound is increasing and attenuates less energy in the microphone signal when the amount of ultrasound is decreasing;
- and
- driving a speaker using the reference audio signal, wherein a path to the speaker includes at least one of a feedforward filter of an acoustic noise cancellation (ANC) subsystem or a transparency filter of a transparency subsystem.
Dependencies are inferred from the claim text.