The influence of military low-altitude flight noise on the inner ear of the guinea pig. Part II: Scanning electron micrographs.

Guinea pigs were exposed once to MLAF noise (126 dB(A), 75 dB/s) and 12 cochleae were prepared for scanning electron microscopy 2 to 3 weeks after exposure. Qualitative analysis of the cilia of the outer hair cells revealed the types of damage already described in literature. The spatial distribution of cilia damage, however, differed essentially from the well known pattern: the damage was more or less pancochlear, beginning in the basal turn and increasing in frequency and severeness of damage till the end of the third turn. The most severe damage was visible in the outer row of the outer hair cells. This special pattern of cilia damage indicates that MLAF noise causes a different type of damage than the types described in literature. More studies are needed.