Evaluation of the relation between audiometric and psychometric measures of hearing after tympanoplasty

The objective of this prospective study was to evaluate the relation between audiometric and psychometric measures after tympanoplasty from the perspective of preoperative selection of patients and postoperative assessment of the results of reconstructive middle ear surgery. Hearing (dis)ability was measured by means of pure-tone audiometry and a validated self-assessment questionnaire: the (modified) Amsterdam Inventory of Auditory Disability and Handicap (m)AIAD. Average hearing thresholds and (m)AIAD scores were evaluated for 80 patients, pre- and 12 months postoperatively. The average improvement of the air conduction threshold in the operated ear was 5.4 ( +/- 14.3) dB; the average improvement in the (m)AIAD score was 2.9 points (+/- 12.1). Although not very strong, the audiometric improvement and increase in (m)AIAD score are significantly related. After the calculation of postoperatively measured mean scores on the (m)AIAD for different 10-dB intervals of postoperative hearing loss averaged over both ears, an interesting relation between the (m)AIAD score and hearing losses emerges. The (m)AIAD score is almost independent of hearing loss for postoperative hearing levels between 25 and 40 dB. Residual hearing loss has to become less than 25 dB before a smaller hearing loss corresponds with a higher (better) (m)AIAD score. For losses larger than 40 dB the (m)AIAD score clearly decreases with increasing hearing loss. Finally, even small residual hearing losses lead, on average, to (m)AIAD scores that are substantially lower than the score for normally hearing subjects. In general, the patient benefit seems related to the magnitude of improvement in the air-conduction thresholds, rather than to the achievement of a certain threshold level. In addition, even small residual hearing losses (less than 25 dB HL) still lead, on average, to (m)AIAD scores that are substantially lower than the scores for normally hearing subjects.