Downlink tone detection and adaptation of a secondary path response model in an adaptive noise canceling system
US9318090B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 2012 |
| Grant date | Apr 19, 2016 |
| Priority date | — |
| Expiry date | Jun 10, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K2210/503
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An adaptive noise canceling (ANC) circuit adaptively generates an anti-noise signal from a reference microphone signal that is injected into the speaker or other transducer output to cause cancellation of ambient audio sounds. An error microphone proximate the speaker provides an error signal. A secondary path estimating adaptive filter estimates the electro-acoustical path from the noise canceling circuit through the transducer so that source audio can be removed from the error signal. Tones in the source audio, such as remote ringtones, present in downlink audio during initiation of a telephone call, are detected by a tone detector using accumulated tone persistence and non-silence hangover counting, and adaptation of the secondary path estimating adaptive filter is halted to prevent adapting to the tones. Adaptation of the adaptive filters is then sequenced so any disruption of the secondary path adaptive filter response is removed before allowing the anti-noise generating filter to adapt.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.