Correlation of pure tone audiogram results and hearing benefit of tympanoplasty for chronic suppurative otitis media

The aim of this study was to evaluate the correlation between pure tone audiogram results and the subjective sensation of hearing benefit of patients who had tympanoplasty for chronic suppurative otitis media. This is a prospective study of 115 patients who had tympanoplasty between 1992 and 1994. The outcome, including a pure tone audiogram and the subjective sensation of hearing benefit, was evaluated at 1 year after operation. There were 63 (55%) patients with subjective hearing benefit after the tympanoplasty. The subjective sensation of hearing benefit correlated with the magnitude of the air conduction (AC) threshold reduction, and increased from 39% for an AC reduction of less than or equal to 10 dB to 100% for an AC reduction of more than 30 dB. The effect of the interaural AC threshold difference on the subjective sensation of hearing was not significant; improvement was felt by 92% of patients when the operated ear became the better hearing ear, and by 73% of patients when the operated ear remained the worse hearing ear. There was considerable discrepancy between the subjective hearing benefit and the pure tone audiogram results. A combination of parameters, including the air-bone gap, the AC threshold, and the subjective hearing change, is recommended in reporting the results of tympanoplasty.