Distortion product otoacoustic emissions in patients with King-Kopetzky syndrome

In the present study, mild impairment of cochlear function in patients with King-Kopetzky syndrome was investigated using DPOAEs. A significant decrease in DPOAE levels in both ears was found in patients with King-Kopetzky syndrome compared with the controls after considering the thresholds as a co-variable. It is noteworthy that the global mean levels of DPOAEs were still significantly greater in controls than in patients with matched thresholds. Further frequency analyses showed a significant decrease in DPOAE levels over the mid- and high-frequency range in patients with better hearing thresholds when compared with those in the control group. Moreover, significantly smaller DPOAEs were found in the ears of patients with King-Kopetzky syndrome and without SOAEs, than in such ears of control subjects after considering the thresholds as a co-variable. However, when SOAEs were present there was no difference. Decreases in DPOAE level appear to represent evidence of minor cochlear pathology, and provide a pathological basis for the difficulty of hearing speech in the presence of background noise, which characterizes King-Kopetzky syndrome.