Multiband programmable compression system
US5278912A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 28, 1991 |
| Grant date | Jan 11, 1994 |
| Priority date | — |
| Expiry date | Jun 28, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2430/03
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An improved audio compressor of the type which is useful in a hearing aid and having a programmable compression ratio is disclosed. In the preferred embodiment, the compressor is used in a hearing aid device of the type which comprises a bandsplit filter to divide an input audio signal into a plurality of frequency bands. Associated with each frequency band is a limiter means which provides variable gain amplification of the input signal as a function of the amplitude of the input signal and as a further function of a programmable control signal. A feedforward means is disposed in parallel to the limiter means, said feedforward means providing a fixed gain signal. The output of the limiter means and the feedforward means are combined at a summing node which forms the input to a variable gain amplifier. Associated control circuitry allows the limiter gain to be programmed to meet the needs of an individual user. The compressor has a variable compression ratio in the form of a sigmoid function.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.