Effects of consecutive wideband tympanometry trials on energy absorbance measures of the middle ear.
OBJECTIVE
Wideband acoustic immittance (WAI) is a new technique for assessing middle ear transfer function. It includes energy absorbance (EA) measures and can be acquired with the ear canal pressure varied, known as wideband tympanometry (WBTymp). The authors of this study aimed to investigate effects of consecutive WBTymp testing on EA.


METHODS
Data were collected in 29 young adults with normal hearing and middle ear status. Before and after 8 successive WBTymp runs, EA was also measured at ambient pressure. Subsequently, two 226-Hz tympanometry tests were performed.


RESULTS
EA systematically changed over the WBTymp trials in a frequency-specific manner: increase for low frequencies (below 1.5 kHz) and decrease for high frequencies (around 2 kHz and 5 to 6 kHz). The changes, although small, were significant. Much larger EA changes were measured at ambient pressure. The test-retest difference of 226-Hz tympanogram measures was much smaller than previously reported.


CONCLUSIONS
Consecutive tympanometry testing alters EA measures of the middle ear. This phenomenon could be mainly attributed to change in stiffness at the eardrum, called tympanometric preconditioning. This also has effects on baseline WBTymp outcomes. This effect should be taken into account as a procedural variable in both research and clinical applications of WAI measurements.
Laina M
LM
Burdiek
Xiao-Ming
XM
Sun
D000158:Acoustic Impedance Tests / Q000379:methods; D000293:Adolescent; D000328:Adult; D004432:Ear, Middle / Q000502:physiology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D010897:Pitch Discrimination / Q000502:physiology; D011312:Pressure; D013018:Sound Spectrography; D055815:Young Adult