Method and apparatus for changing the frequency content of an input signal and for changing perceptibility of a component of an input signal
US6738445B1 · kind B1 · utility
Assignees
Inventor
Key dates
| Filing date | Nov 26, 1999 |
| Grant date | May 18, 2004 |
| Priority date | — |
| Expiry date | Nov 26, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/03828
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
There is disclosed a method and apparatus for changing the frequency content of an input spectrum and a method and apparatus for reducing the perceptibility of a component of an input signal. The first aspect involves adjusting frequency components of the input spectrum in response to a time varying adjustment frequency spectrum to produce an output frequency spectrum including adjusted frequency components of the input spectrum. The time varying input spectrum may be produced by selectively addressing a number of individual sub-spectra at different times. In addition, the input spectrum may be divided into a plurality of sub-spectra and each sub-spectrum may be operated on separately by a different adjustment frequency spectrum at different times. In addition, a perceptual model may be used to enhance the adjustment of the input spectrum or sub-spectra. The second aspect involves adjusting frequency components of a first analysis windowed frame of input time samples in response to an adjustment frequency spectrum, to produce an output frame of output time samples and synthesis windowing the output frame to produce a synthesis windowed frame of output time samples representing a ti…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.