THE EFFECT OF IMPULSE INTENSITY AND THE NUMBER OF IMPULSES ON HEARING AND COCHLEAR PATHOLOGY IN THE CHINCHILLA
THE EFFECT OF IMPULSE INTENSITY AND THE NUMBER OF IMPULSES ON HEARING AND COCHLEAR PATHOLOGY IN THE CHINCHILLA
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DOI：
10.1121/1.394632
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发表时间：
1987-04-01
影响因子：
2.4
通讯作者：
SALVI, RJ
中科院分区：
文献类型：
--
作者：
HAMERNIK, RP;PATTERSON, JH;SALVI, RJ
四十一龙猫，分为七组，暴露于1，10，或100个噪声脉冲（每3秒一个）具有峰值强度为131，135，139，或147分贝。在暴露前后使用回避条件反射程序测量每只动物的听力阈值;在暴露后约90天进行耳蜗感觉上皮细胞的表面制备。永久性阈移的量与暴露的严重程度之间通常存在有序关系，平均组织学数据与听力测量数据之间也大致一致。对于本研究中使用的脉冲，存在一个强度范围，其在高侧以仅用单脉冲暴露产生损伤的强度为界，在低侧以临界强度为界，低于该临界强度，随着脉冲强度的降低，损伤电位急剧下降。对于本实验的曝光条件，该区域仅约10-15 dB宽。在该区域内，损伤阈值是恒定的总能量;即，10分贝的强度变化意味着阈值损伤的脉冲数变化10倍。暂时性和永久性阈值偏移，耳蜗病理，和暴露变量之间的详细关系进行了讨论，这些数据的影响，暴露标准的发展。
Forty-one chinchillas, divided into seven groups, were exposed to 1, 10, or 100 noise impulses (one every 3 s) having peak intensities of 131, 135, 139, or 147 dB. Hearing thresholds were measured in each animal before and after exposure using an avoidance conditioning procedure; a surface preparation of the cochlear sensory epithelia was performed approximately 90 days after exposure. There was generally an orderly relation between the amount of permanent threshold shift and the severity of exposure, and a general agreement between averaged histological data and the audiometric data. For the impulses used in this study, there is a range of intensities which is bounded on the high side by the intensity which just produces injury with single impulse exposures and bounded on the low side by a critical intensity below which the injury potential drops precipitously with a reduction of impulse intensity. This region is only about 10-15 dB wide for the exposure conditions of this experiment. Within this region, the threshold of injury is a constant total energy; i.e., 10-dB change of intensity implies a tenfold change in the number of impulses for threshold injury. Detailed relations between temporary and permanent threshold shift, cochlear pathology, and exposure variables are discussed, as are the implications of these data to the development of exposure criteria.