Which finding best supports a retrocochlear etiology for unilateral hearing loss?

Which finding best supports a retrocochlear etiology for unilateral hearing loss?

• A. Bilateral normal hearing
• B. Unilateral high-frequency SNHL with poor Word Recognition
• C. Normal tympanometry
• D. Normal OAEs

Answer: (B)

The key idea is that retrocochlear pathology shows up as speech understanding that is poorer than would be expected from the degree of pure-tone loss. In a unilateral case, a high-frequency sensorineural hearing loss paired with markedly poor Word Recognition indicates neural transmission problems beyond the cochlea, such as an issue with the auditory nerve. The cochlea can show high-frequency loss, but when speech discrimination is disproportionately worse, it points toward retrocochlear involvement. Normal tympanometry helps rule out middle-ear issues, and normal OAEs don’t exclude neural pathology because OAEs reflect cochlear outer hair cell function, which can be intact even with a retrocochlear problem. So this combination—unilateral high-frequency SNHL with poor Word Recognition—best supports a retrocochlear etiology.

The key idea is that retrocochlear pathology shows up as speech understanding that is poorer than would be expected from the degree of pure-tone loss. In a unilateral case, a high-frequency sensorineural hearing loss paired with markedly poor Word Recognition indicates neural transmission problems beyond the cochlea, such as an issue with the auditory nerve. The cochlea can show high-frequency loss, but when speech discrimination is disproportionately worse, it points toward retrocochlear involvement. Normal tympanometry helps rule out middle-ear issues, and normal OAEs don’t exclude neural pathology because OAEs reflect cochlear outer hair cell function, which can be intact even with a retrocochlear problem. So this combination—unilateral high-frequency SNHL with poor Word Recognition—best supports a retrocochlear etiology.