In a Weber test performed on a patient with sensorineural hearing loss, where does the sound localize?

• A. Better ear
• B. Worse ear
• C. Both ears equally
• D. No sound

Answer: (A)

The Weber test relies on where bone-conducted sound is perceived when one ear has impaired function. In sensorineural hearing loss, the inner ear on the affected side doesn’t transmit the faultless signal as well, so that ear’s perception of the tone is reduced. Because the bone-conducted sound is delivered to both ears, the intact cochlea on the other side picks up the tone more clearly. The brain therefore localizes the sound to the ear with better sensory function—the healthier ear. That’s why the tone is heard louder in the better ear in sensorineural loss. (If the loss were conductive in one ear, the tone would tend to localize to that affected ear due to relatively better bone conduction there.)