Representative confocal microscopy (x 40) of fluorescence stained nuclei within inner and outer hair cells in the cochlea of guinea pigs, 11 days after noise exposure (120 dB, 4 hours). A: Normal levels are observed in the nuclei of inner and outer hair cells of the control subject. The nuclei were arranged normally and no disruption or fragmentations were found. B: The image location is in the third turn of the cochlea after noise exposure, where signs of fragmentation equally occurred throughout both inner and outer hair cells. C: In the second turn of the cochlea, after noise exposure, more disruption and fragmentation appears to occur in the inner and outer hair cell nuclei compared to the third turn of the cochlea. D: The first turn in the cochlea, after noise exposure, exhibited severe disruption and fragmentation compared to the second and third turns in the inner and outer hair cell nuclei.