Hearing aid incorporating a novelty filter
US5396560A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 1993 |
| Grant date | Mar 7, 1995 |
| Priority date | — |
| Expiry date | Mar 31, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R25/502
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
This invention discloses a hearing aid including one or more amplification channels in which each amplification channel includes a bandpass filter establishing the frequency range of that particular channel. Each amplification channel further includes a variable gain amplifier, a short-term energy averaging circuit, a long-term energy averaging circuit and a difference amplifier. An acoustical signal sensed by a microphone associated with the hearing aid is applied to the bandpass filter which then applies a signal within the particular frequency range of that filter to the variable gain amplifier and the short-term energy averaging circuit. An output from the variable gain amplifier is applied to the long-term energy averaging circuit and an earphone for enabling a hearing aid user to perceive the sounds sensed by the microphone. Steady state signals perceived by the microphone are integrated by the long-term energy averaging circuit which causes the difference amplifier to reduce the gain of the variable gain amplifier, thus decreasing the steady state sound. A novel sound sensed by the microphone is integrated by the short-term energy averaging circuit which causes the differenc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.