Long-term effect of acoustic trauma on distortion product otoacoustic emissions in chickens.

Distortion product otoacoustic emissions (DPOAE), 2F1-F2, were measured in chickens before and after exposure to a 1.5-kHz pure tone presented at 120-dB sound-pressure level for 48 h. The low-level component of the DPOAE input/output function was shifted to the right at all frequencies immediately after the exposure with the greatest effect occurring at and above the exposure frequency.