Method and apparatus for automatic volume control in an audio system
US6868162B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 17, 2000 |
| Grant date | Mar 15, 2005 |
| Priority date | — |
| Expiry date | Jan 24, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G5/22
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An audio system (100) is provided with improved adaptive filter (206) to automatically adjust signal gain depending on the ambient noise level. The original music signal passes through a normalized adaptive filter (206), and is subtracted from the ambient room signal detected by a microphone (120), resulting in an error signal that is an estimate of the ambient noise. The error signal is used to update a set of adaptation coefficients so that the normalized adaptive filter more accurately simulates the room transfer function, resulting in an better estimate of the ambient noise. The audio system (100) is calibrated automatically upon initial use to determine adaptation coefficients and noise threshold level to prevent runaway gain. System parameters are adjusted using a controller (124) with a user-friendly interface (400).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.