TY - JOUR
T1 - Occluding the round window causes no change in threshold, but an increase in hearing loss following noise exposure
AU - Perez, Ronen
AU - Sichel, Jean Yves
AU - Adelman, Cahtia
AU - Sohmer, Haim
PY - 2009
Y1 - 2009
N2 - Aim: To assess the effects of occluding the round window on the degree of hearing loss following exposure to broad band noise. Design: Following opening of the middle ear bulla in both ears of ten sand rats, auditory nerve-brainstem evoked response (ABR) thresholds were determined in each ear separately using an insert earphone. The round window of one ear was then occluded with super-glue. The opposite ear was sham-operated. ABR thresholds were again assessed immediately. The animals were then exposed to 113 dB SPL broad band noise for 12 hours. 24 hours after the round window was occluded, which was 8-10 hours after the end of the noise exposure, ABR thresholds were again determined in each ear. In four control animals, the round window was blocked, but they were not exposed to noise. Results: Following the noise exposure, the mean ABR threshold elevation in the round window blocked ears (54,5 ± 5.5 dB) was significantly (p < 0.004) greater than that in the sham-operated ear (40.5 ± 8.6 dB). In the four control ears, there was no change in ABR threshold 24 hours after the round window was occluded.
AB - Aim: To assess the effects of occluding the round window on the degree of hearing loss following exposure to broad band noise. Design: Following opening of the middle ear bulla in both ears of ten sand rats, auditory nerve-brainstem evoked response (ABR) thresholds were determined in each ear separately using an insert earphone. The round window of one ear was then occluded with super-glue. The opposite ear was sham-operated. ABR thresholds were again assessed immediately. The animals were then exposed to 113 dB SPL broad band noise for 12 hours. 24 hours after the round window was occluded, which was 8-10 hours after the end of the noise exposure, ABR thresholds were again determined in each ear. In four control animals, the round window was blocked, but they were not exposed to noise. Results: Following the noise exposure, the mean ABR threshold elevation in the round window blocked ears (54,5 ± 5.5 dB) was significantly (p < 0.004) greater than that in the sham-operated ear (40.5 ± 8.6 dB). In the four control ears, there was no change in ABR threshold 24 hours after the round window was occluded.
KW - cochlear mechanics
KW - hearing loss
KW - noise
KW - protection
KW - round window
KW - temporary threshold shift
UR - http://www.scopus.com/inward/record.url?scp=70350068111&partnerID=8YFLogxK
U2 - 10.1515/JBCPP.2009.20.3.197
DO - 10.1515/JBCPP.2009.20.3.197
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C2 - 19852307
AN - SCOPUS:70350068111
SN - 0792-6855
VL - 20
SP - 197
EP - 206
JO - Journal of Basic and Clinical Physiology and Pharmacology
JF - Journal of Basic and Clinical Physiology and Pharmacology
IS - 3
ER -