Ambient detector for dual mode ANC
AssigneeGoogle Inc.
InventorsSteve Rui, Govind Kannan
Life of this patent
Estimating the term…
Abstract
Active noise cancellation systems and methods include a feedforward path configured to receive a reference signal comprising ambient noise and adaptively generate an anti-noise signal to cancel the ambient noise. The adaptive filter is tuned in accordance with at least one parameter, which is set by a logic device configured to determine an ambient noise condition based the reference signal by estimating a fullband power of the reference signal, estimating a low-frequency power of the reference signal, comparing the fullband power and low-frequency power to one or more thresholds, and/or setting one or more ambient noise flags. The ambient noise condition may include a quiet background, a wideband noise condition, and/or a low-frequency dominant noise condition.
Claims20
An active noise cancelation system comprising:
- a feedforward path comprising an adaptive filter configured to receive a reference signal corresponding to ambient noise and adaptively generate an anti-noise signal to cancel the ambient noise;
- and
- a logic device configured to:
- determine a fullband power of the reference signal;
- determine a low-frequency power of the reference signal;
- determine an ambient noise condition based at least in part on the reference signal;
- and
- select a current ambient sound mode from a set of three or more sound modes based at least in part on determining whether the fullband power of the reference signal and the low-frequency power of the reference signal correspond to wideband noise and not low-frequency dominant noise.
A method comprising:
- receiving a reference signal corresponding to ambient noise;
- adaptively generating an anti-noise signal to cancel the ambient noise;
- determining a fullband power of the reference signal;
- determining a low-frequency power of the reference signal;
- determining an ambient noise condition based at least in part on the reference signal;
- and
- selecting a current ambient sound mode from a set of three or more sound modes based at least in part on determining whether the fullband power of the reference signal and the low-frequency power of the reference signal correspond to wideband noise and not low-frequency dominant noise.
One or more non-transitory, machine-readable media having machine-readable instructions thereon which, when executed by one or more processing devices, cause the one or more processing devices to perform operations comprising:
- receiving a reference signal corresponding to ambient noise;
- adaptively generating an anti-noise signal to cancel the ambient noise;
- determining a fullband power of the reference signal;
- determining a low-frequency power of the reference signal;
- determining an ambient noise condition based at least in part on the reference signal;
- and
- selecting a current ambient sound mode from a set of three or more sound modes based at least in part on determining whether the fullband power of the reference signal and the low-frequency power of the reference signal correspond to wideband noise and not low-frequency dominant noise.
Dependencies are inferred from the claim text.