Weber Test

Excerpt

Tuning fork tests have been the mainstay of otologic examination for more than a century. The Weber test has been mainly used to establish a diagnosis in patients with unilateral hearing loss to distinguish between conductive and sensorineural hearing loss. The Weber test is a useful, quick, and simple screening test for evaluating hearing loss. The test can detect unilateral conductive and sensorineural hearing loss. The outer and middle ear mediate conductive hearing. The inner ear mediates sensorineural hearing. The Weber test is often combined with the Rinne test to detect the location and nature of the hearing loss.

In conductive hearing loss, the sound should lateralize to the affected side; however, in patients with sensorineural hearing loss, the sound lateralizes to the contralateral side. The mechanism underlying sound lateralization of the Weber test has been intriguing to health professionals for many decades. Clinical and animal studies have shown that cochlea is stimulated by bone conduction mainly through two routes:

1. The vibration of the middle ear ossicles

2. Vibrations of the skull itself

In patients with unilateral sensorineural hearing loss, the phase differences and intercochlear intensity lead to vibrations being sensed louder in the contralateral normal ear, causing sound lateralization.