| Autor: |
Russell R. Pfeiffer, Gottfried von Bismarck |
| Rok vydání: |
1967 |
| Předmět: |
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| Zdroj: |
The Journal of the Acoustical Society of America. 42:1156-1156 |
| ISSN: |
0001-4966 |
| DOI: |
10.1121/1.2143914 |
| Popis: |
The sound pressure at the eardrum of anesthetized chinchillas was measured with a probe‐tube microphone implanted into the external auditory meatus. The ratio of this pressure to the free‐field pressure measured at a point corresponding to the center of the animal's head was determined as a function of frequency (sound pressure transformation function, SPTF). Two distinctly different types of SPTF's were found. They differed by as much as 15 dB in the frequency range 1–8 kHz. Several of the ears that exhibited one type of SPTF showed slight perforations in the tympanic membranes. It appeared that a static pressure difference across the eardrum was responsible for the other type of naturally occurring SPTF's. Both types of SPTF's could be artificially produced by either creating or by equalizing static middle‐ear pressure. [This work was carried out at the Massachusetts Institute of Technology and supported in part by the National Institute of Health (Grant), the Joint Services Electronics Program, and NAS... |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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