Modulated gain audio control and zipper noise suppression techniques using modulated gain
US8249275B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 2009 |
| Grant date | Aug 21, 2012 |
| Priority date | — |
| Expiry date | Apr 20, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45522
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A modulated gain audio control and zipper noise suppression techniques provide reduction in audible artifacts caused by discrete-valued gain changes. The gain of a signal is controlled by modulating between multiple gain values for corresponding time durations, so that a resulting average gain is controlled according to the average of the multiple gain values as weighted by their corresponding time durations. The modulation frequency is above the bandwidth of the signal. Transitions between gain levels are performed by changing the relative proportion of the durations to slowly change the gain according to a transition profile, which may be linear or non-linear. The modulation employed may be pulse-width modulation, or another modulation pattern such as a delta-sigma modulation pattern.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.