Internal dynamic range control in an adaptive noise cancellation (ANC) system
US9369798B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 2013 |
| Grant date | Jun 14, 2016 |
| Priority date | — |
| Expiry date | Mar 3, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2460/01
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A personal audio device, such as a headphone, includes an adaptive noise canceling (ANC) circuit that adaptively generates an anti-noise signal using one or more microphone signals that measure the ambient audio. The anti-noise signal is combined with source audio to provide an output for a speaker. The anti-noise signal causes cancellation of ambient audio sounds that appear in the microphone signals. A processing circuit uses the reference microphone to generate the anti-noise signal using one or more adaptive filters. The processing circuit also includes low-pass filters that remove quantization noise images at the output of the adaptive filter to reduce the dynamic range required at the output of the adaptive filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.