Method for improving acoustic sidetone suppression in hands-free telephones
US6618481B1 · kind B1 · utility
11Cited by
2References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 14, 2000 |
| Grant date | Sep 9, 2003 |
| Priority date | — |
| Expiry date | Oct 29, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method for improving acoustic sidetone suppression in hands-free telephones, in particular for use in motor vehicles, is described. The telephone has a level discriminator and a plurality of adaptive echo compensation filters each processing a subband. In at least one subband, a further adaptive filter (a shadow filter) of a lower order is connected in parallel with the adaptive echo compensation filter. Spatial changes are detected with the aid of a combined evaluation of a correlation analysis and a residual error comparison of the two competing, adaptive filters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.