Multifrequency tympanometry: effects of ear canal volume compensation on middle ear resonance

Sweep frequency tympanograms compensating for ear canal volume at 200 and -400 daPa were obtained on 106 ears of 53 subjects during four different sessions. Resonance frequencies were obtained and analyzed to determine normative data, resonance differences between the compensation methods, and the interaction effect of running consecutive tympanograms. There were no gender or interaural differences for either compensation method. Although statistically significant, the compensation method by order interaction found between the first and second runs of tympanograms was not clinically significant. Compensation at 200 daPa was recommended when using sweep frequency tympanometry. Mean resonance frequency difference of the two compensation methods was 400 Hz. Large intersubject variability emphasized the need for audiologists to use proper compensation norms when examining middle ear resonance.