Weber Test - Considerations and Limitations

Considerations and Limitations

This Weber test is most useful in individuals with hearing that is different between the two ears. It cannot confirm normal hearing because it does not measure sound sensitivity in a quantitative manner. Hearing defects affecting both ears equally, as in Presbycusis will produce an apparently normal test result.

Weber test considerations The Weber test reflects conduction loss in the ipsilateral ear because, in the event of impaired conduction, ipsilateral sensorineural hearing is perceived as louder; this is the same reason humming becomes more salient when covering the ears.

If the Weber-lateralized ear has a positive Rinne test (AC>BC), that generally means the absence of conduction loss in that ear, and the reason sound had been perceived as louder on that side is because a sensorineural loss is present contralaterally; an ipsilateral negative Rinne test (BC>AC), on the other hand, would confirm ipsilateral conductive hearing loss (although contralateral sensorineural hearing loss may still be present.

If the Weber-lateralized ear has a positive Rinne test and the contralateral ear has a negative Rinne test, then both conductive and senorineural hearing loss are present in the contralateral ear. This is because sensorineural deficits always take auditory precedent over conductive ones, so even though conductive hearing loss is present in the contralateral ear, it is the sensorineural deficit that is responsible for the ipsilateral perceived elevation of volume.

This also means that a Weber-lateralized ear with bilateral negative-Rinne corresponds to only sensorineural hearing on the ipsilateral side not being affected.

Rinne test considerations Although no replacement for formal audiometry, a quick screening test can be made by complementing the Weber test with the Rinne test.

The Rinne test is used in cases of unilateral hearing loss and establishes which ear has the greater bone conduction. Combined with the patient's perceived hearing loss, it can be determined if the cause is sensorineural or conductive.

For example, if the Rinne test shows that air conduction (AC) is greater than bone conduction (BC) in both ears and the Weber test lateralizes to a particular ear, then there is sensorineural hearing loss in the opposite (weaker) ear. Conductive hearing loss is confirmed in the weaker ear if bone conduction is greater than air conduction and the Weber test lateralizes to that side. Combined hearing loss is likely if the Weber test lateralizes to the stronger ear and bone conduction is greater than air conduction in the weaker ear.