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Titolo:
Onset overmasking of a brief amplitude increment in a pure tone and sensorineural hearing impairment
Autore:
Cazals, Y; Chays, A; Magnan, J;
Indirizzi:
Univ Mediterranee Aix Marseille II, Fac Med Nord, Lab Otol Neurootol, INSERM,EPI9902, F-13916 Marseille 20, France Univ Mediterranee Aix Marseille II Marseille France 20 seille 20, France
Titolo Testata:
OTOLOGY & NEUROTOLOGY
fascicolo: 3, volume: 22, anno: 2001,
pagine: 356 - 362
SICI:
1531-7129(200105)22:3<356:OOOABA>2.0.ZU;2-J
Fonte:
ISI
Lingua:
ENG
Soggetto:
PSYCHOPHYSICAL TUNING CURVES; VESTIBULAR NEURECTOMY; OLIVOCOCHLEAR BUNDLE; SIMULTANEOUS MASKING; TEMPORAL COURSE; NERVE RESPONSE; MASKED TONES; OVERSHOOT; NOISE; ENHANCEMENT;
Keywords:
onset overmasking; sensorineural hearing impairment; Meniere's syndrome; neurotomy; efferents;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Citazioni:
41
Recensione:
Indirizzi per estratti:
Indirizzo: Cazals, Y Univ Mediterranee Aix Marseille II, Fac Med Nord, Lab Otol Neurootol, INSERM,EPI9902, Blvd P Dramard, F-13916 Marseille 20, France Univ Mediterranee Aix Marseille II Blvd P Dramard Marseille France 20
Citazione:
Y. Cazals et al., "Onset overmasking of a brief amplitude increment in a pure tone and sensorineural hearing impairment", OTOL NEURO, 22(3), 2001, pp. 356-362

Abstract

Hypothesis: The goal of this investigation was to determine, in patients with sensorineural hearing loss who may show an audiologic alteration in onset overmasking, whether different pathologic conditions differ in this respect, and whether patients with a vestibular neurotomy damaging the cochlearefferents will be affected. Background: Auditory detection of brief signals, when presented at the beginning of a simultaneous long masking sound,, may require a higher acousticlevel than when presented after several hundred milliseconds. The proposedexplanation, in terms of auditory nerve fibers adaptation has been based on the observation of a proportionally smaller increase of firing in response to an amplitude increment at the onset of a stimulus. However, this may not explain all the data, and other underlying processes are certainly involved. The degree or type of sensorineural pathologic condition may be a contributing factor. In addition, the cochlear efferent system, which exhibits a time course acid a high-frequency predominance compatible with that of onset overmasking. could be involved. Methods: Onset overmasking of a brief amplitude increment in one pure tonewas examined in 6 normal subjects, 12 patients who had undergone vestibular neurotomy, 8 subjects with Meniere's-like symptoms. 5 subjects with presbyacusis, and 3 patients with a small neuroma. Both ears of all subjects were tested. Detection thresholds, amount of onset overmasking, and differences between the two ears were examined. Results: All results from subjects with presbyacusis and neuroma were within the range observed in the group of normal subjects. In the group of eight Meniere's syndrome patients, four had results outside the normal range, three had deteriorated detection, and one had better detection. Among the 12subjects who had undergone neurotomy, 2 had better detection in the unoperated ear. Conclusions: The results from Meniere's patients indicate that, in addition to the previously reported improved detection threshold for short onset delay, a deterioration of detection thresholds may occur in some subjects. Overall, the results from neurotomized ears do not provide evidence for an involvement of cochlear efferents in this tested psychoacoustic task.

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Documento generato il 05/04/20 alle ore 03:30:42