EXPERIMENTAL STUDY OF ACUTE ACOUSTIC TRAUMA IN INNER EAR / 第二军医大学学报

ABSTRACT

This is an experimental research into acute acoustic trauma free entirely from any explosive factor.The guinea pigs used in the different research groups of this experiment were exposed to narrow band noise of central frequency 1000 Hz and SPL 130 dB for one hour.Then the animals were killed and the cochlear basilar membranes were prepared into specimens at different periods for microscopic examination. Before the animals were exposed to noise, and were killed for preparation of specimens, the threshold values of the evoked potential of the cerebral cortex were respectively determined in the different groups so as to evaluate the hearing.The results show that the hearing loss was more serious and structural modification was slight at the earlier stage(i.e.on the day)and vice versa at the later stage (two weeks after).The mechanism of acoustic trauma may involve two aspects, i.e.local mechanical trauma and metabolic changes.At the earlier stage the main indication is mechanical trauma while at the later stage the structural modification is more evident, which may be induced by local metabolic changes.