Morphological changes of the spiral vessel after rock music exposure.

Morphological changes of the spiral vessels of guinea pig after rock music exposure (110-120 dB SPL, 1-3 h) were investigated. Characteristic of rock music is an almost incessant sound production with narrow dynamic range, and high energy in the low tone area. Morphometrical study showed that the lumina of the spiral vessels have a tendency to dilate at all turns in 1-2-h-exposure groups, but tended to constrict, through only at the 2nd turn, in the group of 3-h exposure. This finding that early dilatation of the spiral vessels later turns into constriction may be one of the causes of noise induced temporary threshold shifts.