Perceptual audio compression based on loudness uncertainty
US5682463A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 6, 1995 |
| Grant date | Oct 28, 1997 |
| Priority date | — |
| Expiry date | Feb 6, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/665
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A new technique for the determination of the masking effect of an audio signal is employed to provide transparent compression of an audio signal at greatly reduced bit rates. The new technique employs the results of recent research into the psycho-physics of noise masking in the human auditory system. This research suggests that noise masking is a function of the uncertainty in loudness as perceived by the brain. Measures of loudness uncertainty are employed to determine the degree to which audio signals are "tone-like" (or "noise-like"). The degree of tone-likeness, referred to as "tonality," is used to determine masking thresholds for use in the compression of audio signals. Tonality, computed in accordance with the present invention, is used in conventional and new arrangements to achieve compression of audio signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.