Tympanometric preconditioning of the tympanic membrane

Area of Science:

• Biomechanics
• Otolaryngology
• Auditory Physiology

Background:

• Preconditioning is a biomechanical phenomenon involving tissue changes from repetitive loading.
• Increased tympanic membrane compliance can result from repeated tympanometric measurements, potentially influenced by pressure change rates.

Purpose of the Study:

• To investigate the effect of varying pressure change rates during tympanometry on ear drum compliance.
• To determine the relationship between initial ear drum compliance and the preconditioning effect.
• To identify tympanic membranes susceptible to retraction pockets based on preconditioning response.

Main Methods:

• 103 adult ears underwent 9 tympanometries at 4 different pressure change rates (50, 100, 200, 400 daPa/s).
• Compliance changes were analyzed across trials and correlated with initial compliance levels.
• The rate of pressure change during tympanometry was a key variable.

Main Results:

• Compliance increased with repeated trials, tending towards a steady state.
• A significant correlation (P < 0.001) was found between initial compliance and the degree of preconditioning.
• Ears with high initial compliance (≥ 1.04 cm3) showed less preconditioning and did not always reach a steady state.
• Repeatable compliance measures were achievable after 5 tympanometries.

Conclusions:

• The degree of tympanic membrane preconditioning is dependent on its initial compliance.
• High compliance ears may be less resistant to pressure loads, increasing susceptibility to retraction pockets.
• Five tympanometries are sufficient to obtain reliable compliance measures with minimal preconditioning effects.