ABR, DPOAE, and cochlear microphonic measurements.

(A, B) ABR and DPOAE thresholds were dramatically elevated 0.5 days after noise exposure. There was complete recovery in the low frequencies and partial recovery in the high frequencies. (C) DPOAE growth curves demonstrate similar magnitude emissions between noise-exposed and control mice at 11.3 kHz, the area where we performed the patch-clamp studies. (D) At 32 kHz, a region where there was partial OHC loss, noise-exposed mice had lower DPOAE magnitudes. (E) The cochlear microphonic magnitude measured at the round window using a 6 kHz stimulus was lower in noise-exposed mice compared to controls.