Abstract
We discussed the merging of tinnitus & hyperacusis from the viewpoint of uncomfortable level (UCL) and most comfortable level (MCL). We compared the UCL and MCL between a group of 38 tinnitus patients with no hearing loss (tinnitus group) and a group of 8 normal adults (control group). In the tinnitus group, transiently evoked otoacoustic emission (TEOAE), THI (Newman Japanese version), VAS, SRQD, and AIS were also examined. In the control group, the median UCL was 105dB and MCL was 55dB. The corresponding values in the tinnitus group were 95dB and 40dB. The results of statistical analysis revealed that both the UCL and MCL were significantly reduced in the tinnitus group, and that the severity of tinnitus was correlated with the degree of deterioration of the UCL and MCL. It was thought that the deterioration of UCL·MCL in the tinnitus group suggests the complication of hyperacusis. It is important to estimate hyperacusis by measuring the UCL and MCL during tinnitus therapy.
