Correlation between the Pure Tone Audiometry Results and the Subjective Hearing Benefit of Tympanoplasty

Lee, Won Sang; Lee, Ju Hyoung; Min, Kyung Kun; Cho, Chang Hyun

Abstract

BACKGROUND AND OBJECTIVES: Measuring the therapeutic effect of tympanoplasty is usually dependent on the surgeon's view-point and the results of pre- and post-operative pure tone audiometry (PTA). But there is considerable discrepancy between the subjective hearing benefit and the PTA, so the aim of this study is to evaluate the correlation between them among the patients who had tympanoplasty for chronic suppurative otitis media.
SUBJECTS AND METHOD
One hundred patients who had tympanoplasty between 2000 and 2001 were studied. Patients were divided into two groups, improved and not-improved group, according to their answers to the questionnaire asking his or her subjective hearing benefit. The pre and postoperative air conduction threshold (AC), bone conduction threshold (BC), air-bone gap (ABG) and the amount of increment or decrement of these parameters were compared between the two groups.
RESULTS
Analysis of the data showed significant differences between the two groups with respect to preoperative ABG, postoperative AC, postoperative ABG, AC decrement and ABG decrement. Especially, when the amount of AC decrement was more than 10 dB or the ABG decrement was more than 20 dB, the rate of improved subjective hearing group was increased very strongly.
CONCLUSION
Among the pre- and post-tympanoplasty PTA results, the most useful indicators of patient's subjective hearing benefit are the amount of AC decrement (more than 10 dB) and ABG decrement (more than 20 dB).