Psychoacoustic tuning curves and averaged electroencephalic responses in a patient with low-frequency sensory-neural...

A 10-year-old girl whose bilateral, low-frequency, sensory-neural hearing loss had been noted three years earlier showed a drop in speech discrimination in her left ear with no corresponding decrease in pure-tone sensitivity. Psychoacoustic tuning curves and middle-component averaged electroencephalic responses to tone-pips suggested that damage to the left ear had become greater than indicated by the pure-tone audiogram, accounting for the drop in speech discrimination. This case suggests caution in inferring the magnitude of damage to the peripheral auditory system from tonal thresholds.