抄録
To make short of the above mentioned results, c5 dip appears with distinguished individuality. At first its characteristics seem to be related to a certain factor connected directly with the mode of the auditory middle ear muscle reflex. The bulging type of the tympanic membrane response, in which the stapedius muscle plays the principal role has some resistance to acoustic trauma.
On the other hand, the reaction form to soundstimulation of the native tonus of the sympathetic nervous function co-relates to c5dip.
The tendency corresponding to the V4 type of Dresel's adrenalin test (labile type) after noise exposure, produces resistance to acoustic trauma.
Furthermore, the latent deficiency of thiamine seems to make a disposition to easily cause c5dip. For prevention of acoustic trauma, it is desirable to relieve the violent angioneurotic disorder and promote the inner ear anaerobic metabolism.
For this purpose it is very appropriate to use thiamine. Concerning the occurrence of c5dip, a certain factor other than acoustic trauma for instance, angiovascular phenomenon will be surely participated in the ground and it should have a correlation with bearing noise-susceptibility.
