Close talk detector for noise cancellation
US9094744B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 2012 |
| Grant date | Jul 28, 2015 |
| Priority date | — |
| Expiry date | Oct 25, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2499/11
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A close talk detection method and system is provided for active noise cancellation system on a cellular telephone or the like, based on two properly located microphones. Given the location of the microphones and the way people use the phone, the power ratio (difference) at the two microphones implies the location of the speaker within a given range. The improved close-talk detector is not affected by power levels or SNR of non-close-talk ambient disturbances. Power levels of both a voice and a reference microphone are measured and the ratio r of these power levels is determined. If the ratio r is greater than a predetermined threshold (e.g., 7 dB), then close talk is occurring. If the ratio r is less than the predetermined threshold, then the signal is determined to be loud ambient noise or some other non-close-talking signal and noise cancellation processing is not affected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.