Effects of consecutive trials and test-retest reliability of 1000-Hz tympanometry in adults

Abstract

Objective: To investigate the effect of consecutive 1000-Hz tympanometry testing on admittance measures, and examine test-retest reliability. Design: Repeated measures with eight trials of 1000-Hz Y_a and B_a/G_a tympanometry, respectively, in two ears of each subject, followed by repeated 226-Hz tympanometry. Study sample: Twenty-seven normal-hearing young adults. Results: For single-peak tympanograms, peak Y_tm and G_tm systematically increased across trials with a mean change of 8% and 15% at Trial 8, respectively, whereas B_tm increased marginally. For notched tympanograms, peak Y_tm and B_tm decreased by 23% and 162% at Trial 8, and G_tm in two cases also decreased (10% on average). Trial 2 and 3 contributed 50% to 70% of the total changes. Test-retest differences of subsequently acquired 1000- and 226-Hz tympanograms were smaller than previously reported. Conclusions: Consecutive testing significantly alters middle-ear admittance in 1000-Hz tympanometry. The outcome is contingent on tympanogram pattern and admittance component: Increase of peak Y_tm and G_tm in single-peak tympanograms and decrease of all measures in notched tympanograms. The present results complement previous studies on our understanding of the mechanism underlying this effect: a decrease of middle-ear stiffness. The effect of repetitive tympanometry should be accounted for in research involving sequential testing.

Key Words::

• 1000-Hz tympanometry
• acoustic admittance
• susceptance
• conductance
• acoustic immittance
• tympanometric preconditioning
• middle ear

Acknowledgements

The Department of Communication Sciences and Disorders at Wichita State University supported the first author's Doctor of Audiology research project in the form of a graduate assistantship and monetary compensation to the participants. A preliminary account of this work was presented at the American Academy of Audiology Annual Convention (Anaheim, CA, USA; April 3–6, 2013).

Declaration of interest: The authors report no conflict of interest. The authors alone are responsible for the writing and content of the paper.