Cholesteatoma Effect on Audiogram
Cholesteatoma characteristically produces a conductive hearing loss on audiogram, with the air-bone gap reflecting the degree of ossicular chain erosion and middle ear involvement. 1, 2
Audiometric Pattern
Conductive hearing loss is the hallmark finding, manifesting as an air-bone gap where bone conduction thresholds remain normal while air conduction thresholds are elevated 2, 3
The air-bone gap directly correlates with the extent of ossicular damage, with more severe gaps indicating greater ossicular erosion 2, 4
Preoperative hearing levels are typically worse in patients with advanced disease requiring canal wall down procedures compared to those with limited disease amenable to intact canal wall techniques 2
Frequency-Specific Characteristics
Hearing loss is most pronounced at frequencies between 500-3,000 Hz, which are critical for speech understanding 2
Unlike Ménière's disease which shows low-to-mid frequency sensorineural hearing loss, cholesteatoma produces conductive loss across frequencies 5
Sensorineural hearing loss is not typically caused by cholesteatoma unless there is erosion into the inner ear structures (lateral semicircular canal involvement) 2
Disease-Specific Variations
Attic cholesteatomas tend to have better hearing outcomes compared to other locations, likely due to less extensive ossicular involvement 2
Children demonstrate worse preoperative and postoperative hearing levels compared to adolescents or adults, with recurrence rates of 13% versus 10% in adults 6, 2
Congenital cholesteatoma may present with progressive conductive hearing loss and a completely normal-appearing tympanic membrane, making it challenging to diagnose without imaging 4, 3
Progressive Nature
Progressive conductive hearing loss with an intact tympanic membrane and soft tissue density in the middle ear on CT should raise high suspicion for open-type congenital cholesteatoma 3
Bilateral cholesteatoma results in worse total postoperative hearing compared to unilateral disease 2
Revision operations and recurrent cholesteatoma are associated with significantly worse hearing outcomes for all analyzed parameters 2
Critical Diagnostic Pitfall
Do not confuse cholesteatoma with sensorineural hearing loss conditions—the presence of an air-bone gap with normal bone conduction distinguishes it from retrocochlear lesions like vestibular schwannoma, which typically show mid-to-high frequency sensorineural loss (especially at 3000 Hz) with minimal fluctuation 5