The purpose of the present study was to determine the threshold (ART), latency, rate, and magnitude of the Acoustic Reflex (AR) for ten recorded environmental noise stimuli. These values were then compared to results obtained with standard white noise and a 1 kHz pure-tone. The latency was measured at threshold, and at 20 dB above the threshold (SL(,R)). The rate and magnitude were measured at 20 dB SL(,R). The measurements were made on 30 normal hearing subjects via an impedance meter. / The results, expressed in median values, suggested that: (1) The ARTs for the environmental noises ranged from 78.83 through 81.78 dB SPL. The ARTs for the white noise, and the pure-tone were 81.38 and 95.19 dB SPL, respectively. For all practical purposes (91%) the ARTs for the environmental noises lie within (+OR-) 5 dB of the ART for the white noise. (2) The latency at threshold for the environmental noises ranged from 452.5 through 552.50 msec. Similarly, the latencies were 402.5 and 487.5 msec for the white noise and the pure-tone, respectively. (3) The latency at dB SL(,R) for the environmental noises ranged from 152 through 180 msec. Similarly, the latencies for the white noise and the pure-tone were 152.5 and 181.0 msec, respectively. There was a decrease in latency at 20 dB SL(,R) compared to that at threshold across all the stimuli. (4) The contraction rate at 20 dB SL(,R) for all stimuli ranged from .0009 through .0011 cc/msec. (5) The contraction magnitude at 20 dB SL(,R) for all the environmental noises and the white noise ranged from .669 through .816 cc. However, the magnitude for the pure-tone was .867 cc which was higher than all the noises. / In conclusion, the answers obtained for the five experimental questions investigated provide data which is similar for the environmental noises and the white noise. / Source: Dissertation Abstracts International, Volume: 42-06, Section: B, page: 2296. / Thesis (Ph.D.)--The Florida State University, 1981.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_74551 |
| Contributors | SMITH, MARSHALL MELVIN., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 114 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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