Best of five
- A. Otoacoustic emission amplitude only
- B. Stapedial reflex decay
- C. Endocochlear potential
- D. Interaural time difference
- E. Vestibulo-ocular reflex gain
FRCS (ORL-HNS) · SECTION 1 SBA
Sound localisation
A patient with unilateral conductive hearing loss struggles to localise sounds. Which binaural cue is most disrupted for low-frequency sounds?
D. Interaural time difference
Low-frequency localisation relies mainly on phase and arrival-time differences between ears; unilateral attenuation and delay degrade this comparison. High frequencies depend more on interaural level differences.
Why every option is right or wrong
A. Otoacoustic emission amplitude only: Emissions measure outer-hair-cell function, not the binaural localisation computation.
B. Stapedial reflex decay: This is a diagnostic measure rather than the principal cue.
C. Endocochlear potential: This supports transduction but does not encode direction between ears.
D. Interaural time difference: Low-frequency localisation relies mainly on phase and arrival-time differences between ears; unilateral attenuation and delay degrade this comparison. High frequencies depend more on interaural level differences.
E. Vestibulo-ocular reflex gain: This stabilises gaze during head movement.
What if the scenario changed?
If the signal were high frequency, head-shadow-related interaural level differences would dominate.
Independent Clinora educational preparation material; not official JCIE content, an accredited programme, clinical advice, or a substitute for current guidance, local policy and specialist judgement.
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