Method and apparatus for reducing background noise in communication systems and for enhancing binaural hearing systems for the hearing impaired
US5289544A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 31, 1991 |
| Grant date | Feb 22, 1994 |
| Priority date | — |
| Expiry date | Dec 31, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R25/407
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Directional hearing in noisy environments is enhanced using small conventional microphones. In one embodiment a conventional first order bidirectional gradient microphone is employed in connection with a barrier to produce sound shadow at the rearward end of the microphone. In other embodiments such as hearing assistive devices worn on a person's head or body, the head or body of that person serves as the barrier. The result is a significant reduction in gain for all frequencies of acoustic energy emanating from generally rearward of the microphone. The sound shadow creates an apparent change of direction of arrival for rearwardly arriving acoustic energy, thereby making it appear to the microphone that the sound is approaching from the high attenuation 90.degree. direction. Two spaced bidirectional microphones worn on a person's body may be positioned to take advantage of this effect while simulating binaural hearing in an assistive listening device. A similar directional result is obtained with two conventional cardioid microphones mounted on a common casing to face in opposite directions. Electronic circuitry subtracts the output signal of the rearward facing microphone from the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.