Tinnitus and 2fl-f2 distortion product otoacoustic emissions following salicylate overdose

A 22-year-old woman consumed approximately 10 g of salicylate with suicidal intent. She had a severe hearing loss and a strong tinnitus within 22 h of the overdose, and then 24 h later a subsequent hearing restoration and tin nitus abolishment. Transiently evoked otoacoustic emissions (TEOAEs) and 2f 1 - f2 distortion product otoacoustic emissions (DPOAEs) were measured in b oth states. in the state of intoxication DPOAEs could be recorded well in t he frequency range that corresponded to the appearance of the tinnitus desp ite the 50-dB bearing loss. The corresponding DPOAE I/O-functions were line arized, indicating loss of-outer hair cell compression. After recovery, DPO AE level and DPOAE growth were within the normal range and showed normal ph ysiological compression. The TEOAEs were missing in the acute state of into xication. This case supports the hypothesis that aspirin-induced tinnitus i s generated at the outer hair cell lever. Whereas TEOAEs only give evidence that something might have changed in the cochlea, DPOAEs are a more useful and robust quantitative indicator of the underlying mechanism of some form s of cochlear tinnitus. (C) 2000 Acoustical Society of America. [S0001-4966 (00)03003-4].