Weber test

The Weber test is a test for determining a lateralization of the sense of hearing using a tuning fork. He is, together with the Rinne test, a standard test of Oto- Rhino-Laryngology for the investigation of hearing loss.

In the Weber test, the foot of a vibrating tuning fork is placed to the subject on the crown. The sound is transmitted via bone conduction phase in both inner ears. The normal hearing hears the sound of the tuning fork in both ears equally, he therefore has the impression to hear this in the middle of the head, the tone is not lateralized (Latin latus = side). Specifies the subject, to hear the sound on one side, one speaks of a " lateralization " ( lateralization ). This is the case with a one-sided or asymmetrical hearing loss.

In a unilateral sensorineural hearing loss the sound from better hearing ( normal ) inner ear is perceived louder, so the patient lateralized to the healthy ear. In a unilateral conductive hearing loss in the affected ear but the sound is heard louder, usually to the surprise of the patient.

After the Mach sound drainage theory is transferred from an intact middle ear sound energy from the inner ear via the ossicles to the tympanic membrane and is radiated into the air. This part of the tuning fork via bone conduction directly to the inner ear supplied acoustic energy that is normally not found in the inner ear to the effect. But if the middle ear is not able to transmit the sound correctly ( middle ear deafness ), these sound energy remains in the inner ear, the sound is perceived louder in that ear than in the healthy ear the other side.

Thus, the Weber test allows for a one-sided hearing loss, a rapid and reliable distinction between sensorineural hearing loss and conductive hearing loss, ie for example between a sudden hearing loss and OME.

History

The name of the test after Ernst Heinrich Weber (1795-1878), professor of anatomy and physiology in Leipzig, based on a publication of Weber from the year 1834. However, Weber described in his publication actually only the occlusion in the healthy ear, before him was described by Charles Wheatstone and later at the Bing test was applied. The first description of the lateralization of the pathological ear - even in the sensorineural hearing loss - likely by Eduard lard, hearing and speech doctor in Dresden, (1846 ) submitted. The value of the Weber test was in the second half of the 19th century, even by well-known otologist doubts ( Hermann Schwartze ) or at least relativized ( Friedrich Bezold, Adam Politzer ).

For further tuning fork tests see also: Bing test, Gellé test, Rinne test.