LACK OF ASSOCIATION BETWEEN TRANSIENTLY EVOKED OTOACOUSTIC EMISSION AMPLITUDE AND EXPERIMENTATION LINKED-FACTORS (REPEATED ACOUSTIC STIMULATION, CEREBROSPINAL-FLUID PRESSURE, SUPINE AND SITTING POSITIONS, ALERTNESS LEVEL)

Changes in transiently evoked otoacoustic;emissions (TEOAEs) occur dur ing sleep and during tasks requiring attention. This can be due to a c entral nervous system effect on the cochlea. But, an additional or dom inant influence by non-controlled factors is possible. In this paper, the effect of click-stimulus repetition, lying and sitting positions, state of alertness (awake or asleep) and CSF pressure variation on TEO AE features were studied. None of these factors affected TEOAE amplitu de. In 2 subjects, TEOAE amplitude increased considerably during the n ight while remaining stable in 7 subjects during daytime sleep. This m ay be due to circadian variations of TEOAE amplitude.