Noise cancelling apparatus for a telephone handset
US5239578A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1990 |
| Grant date | Aug 24, 1993 |
| Priority date | — |
| Expiry date | May 15, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M1/19
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An improved noise cancelling apparatus is disclosed combining a unique directional noise cancelling microphone structure with a noise reducing, signal shaping electronic circuit. The microphone structure simultaneously receives two input signals; a first signal containing only ambient noise and a second signal containing both ambient noise and a voice signal. The microphone structure cancels the two noise components and transmits the voice signal into an electrical signal. The electronic circuit further processes the electrical signal to suppress any noise components not cancelled by the microphone structure. The electronic circuit also functions to enhance the high frequency components of the voice signal to provide a richer, more pleasant sounding output. Because the unique microphone structure is combined with the electronic circuit the noise cancelling apparatus of the present invention provides a cleaner, more pleasant sounding output than that of the prior art.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.