Active noise cancellation for wearable head device
Examples of the disclosure describe systems and methods for reducing audio effects of fan noise, specifically, for a wearable system. A method wherein operating a fan of a wearable head device; detecting, with a microphone of the wearable head device, noise generated by the fan; generating a fan reference signal, wherein the fan reference signal represents at least one of a speed of the fan, a mode of the fan, a power output of the fan, and a phase of the fan; deriving a transfer function based on the fan reference signal and based further on the detected noise of the fan; generating a compensation signal based on the transfer function; and while operating the fan of the wearable head device, outputting, by a speaker of the wearable head device, an anti-noise signal, wherein the anti-noise signal is based on the compensation signal.
1 . A method comprising:
operating a fan of a wearable head device;
detecting, with a microphone of the wearable head device, noise generated by the fan;
generating a fan reference signal;
deriving a transfer function based on the fan reference signal and based further on the detected noise of the fan;
generating a compensation signal based on the transfer function; and
while operating the fan of the wearable head device, outputting, by a speaker of the wearable head device, an anti-noise signal, wherein the anti-noise signal is based on the compensation signal.
2 . The method of claim 1 , wherein the fan reference signal represents at least one of a speed of the fan, a mode of the fan, a power output of the fan, and a phase of the fan.
3 . The method of claim 1 , wherein the anti-noise signal reduces a level of fan noise received at a second microphone.
4 . The method of claim 1 , wherein the anti-noise signal reduces a level of fan noise received at an ear canal of a user of the wearable head device.
5 . The method of claim 1 , wherein the transfer function comprises a fan-to-microphone transfer function.
6 . The method of claim 1 , wherein the transfer function comprises a fan-to-ear transfer function.
7 . The method of claim 1 , wherein the noise comprises a frequency in a range of 0 to 4 kHz.
8 . The method of claim 1 , wherein the operating the fan comprises revolving the fan at a rate of 800-5000 revolutions per minute.
9 . The method of claim 1 , further comprising:
changing an operation of the fan from a first state to a second state;
detecting, with the microphone, noise of the fan operating at the second state;
updating the fan reference signal based on said changing of the operation;
deriving a second transfer function based on the updated fan reference signal and based further on the detected noise of the fan operating at the second state;
generating a second compensation signal based on the second transfer function; and
concurrently with the operating the fan at the second state, outputting, by the speaker, a second anti-noise signal, wherein the second anti-noise signal is based on the second compensation signal.
10 . The method of claim 1 , wherein:
the wearable head device comprises an acoustic echo canceller;
the deriving the transfer function is performed via the acoustic echo canceller; and
the generating the compensation signal is performed via the acoustic echo canceller.
11 . The method of claim 1 , further comprising:
receiving a second compensation signal, wherein the second compensation signal comprises an output of a deep neural network (DNN) based subtraction based on a recorded sound; and
outputting, by the speaker of the wearable head device, a second anti-noise signal, wherein the second anti-noise signal is based on the second compensation signal and is configured to reduce a level of noise associated with the recorded sound.
12 . The method of claim 1 , wherein the anti-noise signal comprises a periodic signal.
13 . The method of claim 1 , further comprising receiving a speaker reference signal, wherein the transfer function is further based on the speaker reference signal.
14 . The method of claim 1 , further comprising:
detecting a speaker feed signal from the speaker; and
in response to detecting the speaker feed signal, reducing a level of the speaker feed signal.
15 . The method of claim 1 , further comprising aligning a phase of the anti-noise signal with a phase of the noise generated by the fan.
16 . The method of claim 1 , wherein the anti-noise signal comprises signals having frequencies below 4 kHz.
17 . A system comprising:
a wearable head device comprising a fan, a microphone, and a speaker; and
one or more processors configured to perform a method comprising:
operating the fan;
detecting, with the microphone, noise generated by the fan;
generating a fan reference signal;
deriving a transfer function based on the fan reference signal and based further on the detected noise of the fan;
generating a compensation signal based on the transfer function; and
while operating the fan of the wearable head device, outputting, by the speaker, an anti-noise signal, wherein the anti-noise signal is based on the compensation signal.
18 . A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform a method comprising:
operating a fan of a wearable head device;
detecting, with a microphone of the wearable head device, noise generated by the fan;
generating a fan reference signal;
deriving a transfer function based on the fan reference signal and based further on the detected noise of the fan;
generating a compensation signal based on the transfer function; and
while operating the fan of the wearable head device, outputting, by a speaker of the wearable head device, an anti-noise signal, wherein the anti-noise signal is based on the compensation signal.