Which test is used primarily to detect middle ear effusion rather than to assess hearing thresholds?

• A. Acoustic reflectometry
• B. Audiometry
• C. Auditory brainstem response (ABR)
• D. Evoked otoacoustic emission (EOAE) testing

Answer: (A)

Acoustic reflectometry is focused on the status of the middle ear by measuring how much sound is reflected back from the tympanic membrane. When fluid is present behind the eardrum, the middle ear’s impedance changes and more energy is reflected, making this test effective at detecting middle-ear effusion. It is quick, objective, and does not rely on the patient’s responses, which is ideal for screening for effusion.

Hearing thresholds, on the other hand, are assessed with audiometry, ABR, or EOAE testing. Audiometry requires a patient’s responses to sounds to determine softest audible levels. ABR measures neural pathways to estimate thresholds but is primarily about neural conduction, not middle-ear status. EOAE testing assesses cochlear outer hair cell function and relies on clear transmission through the middle ear; effusion can mask or abolish emissions, making it unsuitable as a primary measure of effusion.