How we do it: tympanoplasty: are different three- and four-frequency averages comparable?

The results of tympanoplasty may be reported in a variety of ways. Pure-tone audiometry underpins reporting, yet there is no constancy in the pure-tone threshold average used. We examine the relationship between the 0.5, 1, 2 kHz, 0.5, 1, 2, 3 kHz and 0.5, 1, 2, 4 kHz pure-tone audiometry averages. Using audiometric data collected for 77 patients, we have compared hearing threshold using three different frequency averages derived from pure-tone audiometry. The 0.5, 1, 2 kHz, 0.5, 1, 2, 3 kHz and 0.5, 1, 2, 4 kHz three- and four-frequency averages are significantly different, this difference being primarily determined by the changes in the 4-kHz threshold. Using an average including 4 kHz results in 8% few patients achieving an ABG closure to within either 10 dB or 20 dB. When comparing surgical results with others, surgeons should use reports employing comparable audiometric measures of analysis.