Active noise reduction system
US4985925A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1988 |
| Grant date | Jan 15, 1991 |
| Priority date | — |
| Expiry date | Jun 24, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K2210/3228
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
Improvement in active noise reduction based on a negative feedback electro-acoustical system which consists of an Electronic Earplug seated in the concha fossa combining active and passive noise reduction in the quiet zone at the ear, a bilateral transducer circuit which drives a speaker as an acoustical velocity source, a shunt feedback control filter network which improves stability and increases noise reduction, and a combined input noise-filter/feedback system. A typical application is in a noisy environment for hearing protection and for improved communication capability, e.g., in vehicular communication, telephone, intercom, hearing aids, and stethoscopes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.