Interaural multiple frequency tympanometry measures: clinical utility for unilateral conductive hearing loss

Area of Science:

• Audiology
• Otoacoustic Emissions
• Hearing Science

Background:

• Tympanometry is a standard clinical tool measuring ear acoustic immittance.
• The 226 Hz tympanogram aids in diagnosing conditions like Eustachian tube dysfunction and middle ear fluid.
• Multiple frequency tympanometry offers greater sensitivity than single-frequency tests for differentiating middle ear pathologies.

Purpose of the Study:

• To establish normative measures of middle ear resonance using multi-frequency tympanometry.
• To calculate 90% ranges for middle ear resonant frequency and interaural differences.

Main Methods:

• Normative data were collected from adult males and females using a mixed design.
• Multi-frequency tympanograms were recorded to estimate middle ear resonant frequency (RF) using various methods.
• Data were analyzed using three-way mixed analyses of variance and t-tests with Bonferroni adjustment.

Main Results:

• A broad range of approximately 500 Hz was observed for middle ear resonance in healthy adults.
• The 90% range for interaural RF difference was approximately ±200 Hz.
• This indicates that the right ear's RF can naturally differ by up to 200 Hz from the left ear's RF.

Conclusions:

• Ninety percent ranges for interaural middle ear resonance differences were established.
• These normative values are crucial for identifying alterations in middle ear mass or stiffness.
• This aids in diagnosing unilateral conductive hearing loss.