Abstract
We examined the time course changes of tinnitus after tympanoplasty in 30 patients. All patients exhibited disorders of symptomatic tinnitus preoperatively. Pitch match test and loudness balance test, in combination with pure tone audiometry were employed to obtain data on their characteristics. The patients were further subdivided into two groups, the middle tone group and the high tone group, based on whether their tinnitus could be pitch-matched relatively to low to middle frequency sounds (125Hz to 1kHz) or high frequency sounds (2 to 8kHz). In addition, a series of questionnaires was administered to both groups to evaluate the following subjective complaints: 1) the degree of loudness, 2) duration period, and 3) the degree of disturbance in daily life.
Fifty-five percent of the patients in the middle tone group and 48% in the high tone group showed changes to the pitch matched frequency 1 week after surgery. One week later, 63% of the patients in the former group still retained altered frequency matching to their tinnitus, whereas the percentage for the latter group decreased to 30% indicating that about 20% of the patients with high tone tinnitus returned to their original conditions. Results from subjective assessment by the questionnaire substantiated the difference in symptom severity between the two groups. Three weeks after the surgery, 70% of the patients in the middle tone group showed decreased scores for subjective loudness, whereas only 25% of the high tone group showed relief. On the other hand, the scores for tinnitus duration periods and the degree of disturbance in daily life remained unchanged after the surgery, and no significant difference was observed between the two groups. Although the relationship between the pathologic conditions of the middle ear cavity and exacerbating parameters of tinnitus is not fully understood, we speculate that tinnitus cases showing lower frequency tone are more likely to be dependent on abnormal sound transmission caused by middle ear diseases.
