Audio spatial enhancement apparatus and methods
US6111958A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 21, 1997 |
| Grant date | Aug 29, 2000 |
| Priority date | — |
| Expiry date | Mar 21, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04S3/002
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A spatial enhancement system broadens the sound image of a stereo signal. The system emphasizes dissimilarity between the left and right channels by (i) boosting the level of the dissimilar components, (ii) providing spectral equalization to enhance the perception of breadth, and (iii) injecting an equalized, attenuated and inverted version of the dissimilar component into the opposite channel to broaden the components stereo image. The present invention avoids spectral coloration by providing a generally flat transfer function from input to output. Interchannel dissimilarity is estimated by performing a first order comparison of the left and right input signals. The comparison may be implemented by a peak detector on the L-R signal, a cross-correlation procedure, or some other scheme. As a feature, a feedback mechanism alters the equalization characteristics of the signals in a manner that is responsive to the dissimilarity of the output signals. For example, the level of the low frequency components is boosted when the left and right output signals are dissimilar. If the input signal is a monophonic signal, the system decorrelates the mono signal using cascades of all pass filter…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.