Medical consequences for hyperacusis and Menière's disease
Before 1995 there was no explanation for the well-documented fact that loudness intolerance (hyperacusis) can be the first symptom in the early stage of Menière's disease.
This disease, which possibly affects up to 1 % of the population, is characterized by attacks of loss of balance (vertigo) in connection with permanent or fluctuating symptoms of hearing loss and phantom sound (tinnitus).
After two large-scale clinical studies (Hallpike and Hood, 1959; Hood and Poole, 1966) it is also known that loudness intolerance is one of the first symptoms of the disease for most patients.
Because loudness intolerance can easily be measured audiometrically, it would have been possible after 1966, at the latest, to introduce a widespread test routine for an early detection of Menière's disease. A sufficiently early diagnosis is a major problem with this disease, because it often remains undetected for many years. An early knowledge, however, would give the patients a chance to adapt their life style and thus avoid some of the serious later symp-toms.
The reason why tests of loudness intolerance have rarely
been used, despite their obvious di-agnostic power, is a simple one. There
was no plausible explanation for the causal connection between symptom
and disease. After the discovery of the damping function of the inner
ear, however, this connection became clear and was published in detail
Braun, M. (1996) Impediment of basilar membrane motion reduces overload protection but not threshold sensitivity: evidence from clinical and experimental hydrops. Hear. Res. 97, 1-10. Abstract
Hallpike, C.S. and Hood, J.D. (1959) Observations upon the neurological mechanism of the loudness recruitment phenomenon. Acta Otolaryngol. (Stockh.) 50, 472-486.
Hood, J.D. and Poole, J.P. (1966) Tolerable limit of loudness: its clinical and physiological significance. J. Acoust. Soc. Am. 40, 47-53.
Nageris B, Adams JC, Merchant SN. (1996) A human temporal bone study of changes in the basilar membrane of the apical turn in endolymphatic hydrops. Am. J. Otol. 17, 245-252. Comment
Xenellis JE, Linthicum FH Jr, Webster P, Lopez R (2004) Basilar membrane displacement related to endolymphatic sac volume. Laryngoscope 114, 1953-1959. Comment
Interesting links: Alec Salt