Adaptive noise canceller
US5473702A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1993 |
| Grant date | Dec 5, 1995 |
| Priority date | — |
| Expiry date | Jun 2, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2410/05
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An adaptive filter estimates the noise component in a primary audio signal by convolving a secondary audio signal with a set of coefficients. The estimated noise component is subtracted from the primary audio signal to produce an output signal. During steady-state operation, the adaptive filter coefficients are updated as to minimize the difference between the primary audio signal and the estimated noise component. Steady-state operation is identified automatically by monitoring the power level of the primary or secondary audio signal, or the power level of the output signal. Coefficient updating is suspended when the monitored power level rises from a steady state to an unsteady state, and is resumed when the monitored power level returns to its previous steady-state level, or settles into a new steady state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.