Variable speed playback system
US5694521A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 1995 |
| Grant date | Dec 2, 1997 |
| Priority date | — |
| Expiry date | Jan 11, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/06
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A variable speed playback system exploits multiple-period similarities within a residual signal, and includes multiple-period template matching which may be applied to alter the excitation periodical structure, and thereby increase or decrease the rate of speech playback. Embodiments of the present invention enable accurate fast or slow speech playback for store and forward applications without changing the pitch period of the speech. A correlated multiple-period similarity measure is determined for an excitation signal within a compressor/expander. The multiple-period similarity enables overlap-and-add expansion or compression by a rational ratio. Energy variations at the onset and offset portions of the speech may be weighted by energy-based adaptive weight windows.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.