[Effects of body posture on cochlear performance].
Experimental research has demonstrated that changes in body position influence auditory function and, specifically, supine position produces a sensorineural hearing loss at low frequencies. The hypotheses to interpret these phenomena are principally referred to an increase of hydrostatic pressure of labyrinthine fluids. In order to evaluate the effects of head position on the cochlear performance a modern test battery has been performed to study cochlear function in 11 normal subjects ranged in age from 22 to 34 years. The tests (Remote Masking:RM; Brief Tone Audiometry:BTA; Critical Ratio:RC) have been evaluated in two positions: sitting upright and supine with the head at a 20 backward angle. The results of our research have shown that in all the cases, the supine position produces a significant shift of the auditory threshold at 250 and 500 Hz, and a decrease of RM values in about all of the cases. We have estimated non statistically significant differences for the RC and BTA values, in more than half of the ears tested. On the basis of the significance given to RM, BTA, RC: we can deduce that the modifications of the auditory performance related to an increase in perilymphatic hydrostatic pressure, induced by the head position are produced by an increase in rigidity of the mechanical vibratory structures of the cochlea rather than the expression of sensorineural damage.
Salonna
I
I
Istituto Policattedra Otorinolaringoiatria Cattedra Audiologia Università di Bari.
Longo
G
G
Bartoli
R
R
D000328:Adult; D001309:Auditory Threshold / Q000502:physiology*; D003051:Cochlea / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011187:Posture / Q000502:physiology*
Effetti della posizione del corpo sulla performance cocleare.