Frequency-dependent ANR reference sound compression
US9123320B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 2013 |
| Grant date | Sep 1, 2015 |
| Priority date | — |
| Expiry date | May 2, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L21/0208
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An active noise reduction (ANR) circuit includes a digital feed-forward ANR pathway coupled to a feed-forward microphone, to detect environmental sounds in an environment external to a casing, and to a first acoustic driver to output sounds within the casing. The digital feed-forward ANR pathway applies a plurality of filters using a first set of coefficients to convert signals from the feed-forward microphone to feed-forward anti-noise sounds to reduce environmental sounds within the casing. In response to a stimulus, the digital feed-forward ANR pathway applies the plurality of filters using a second set of coefficients, which reduce the degree of feed-forward ANR to enable human speech sounds in the environment external to the casing to be conveyed from the feed-forward microphone to the acoustic driver with less reduction than provided by the first plurality of filters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.