Insert earphones for audiometry
US4677679A · kind A · utility
Inventor
Key dates
| Filing date | Jul 5, 1984 |
| Grant date | Jun 30, 1987 |
| Priority date | — |
| Expiry date | Jul 5, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R1/1016
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Insert earphones, which are especially useful for audiometry applications include a transducer which is coupled to a resonance cancellation tube as well as to a main tube which is coupled to the ear, with series acoustic dampers in the tubes, operating in a known manner to obtain a smoothly varying frequency response characteristic. An electrical equalization network is coupled to the transducer, cooperating with the acoustic components to obtain a frequency response characteristic which is either flat or which matches that of the human ear. The dampers in series with the main and cancellation tubes have acoustic resistances which are respectively about 20% lower and 20% higher than the characteristic impedances of such tubes, operating to obtain a broadband increase in output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.