Interpretation of results

In normal hearing, air conduction is better than bone conduction. The tuning fork is heard more clearly when placed in line with the external auditory meatus than when placed on the mastoid process. The result is termed Rinne's positive, or alternatively, may be written as AC > BC.

In the presence of a conductive hearing loss, bone conduction is heard more clearly than air. The result is described as Rinne's negative or may be written BC > AC. It requires a conductive hearing loss of at least 20 decibels.

A Rinne's negative may be:

• 'true' - the patient has a conductive deficit in that ear
• 'false' - the patient has a severe or total sensorineural deficit, but can hear the tone in the "good" ear due to the transfer of sound through the skull base to the functioning cochlear on the other side

A false Rinne's negative should always be considered in:

• any patient who has apparently severe unilateral hearing loss
• any patient with apparently bilateral conductive hearing loss
• any patient in whom the Weber's test is contradictory

To avoid false Rinne's negatives, it is best to "mask" the good ear whilst the suspect ear is being tested, and to always follow the Rinne's test with a Weber's test. The simplest method of masking the non-test ear is to massage the tragus; alternatively, a Barany noise box may be used.

Note:

• studies have shown that the Rinne test had good specificity but only modest sensitivity (1)
• in older patients, the Rinne test which differentiates conductive from sensorineural (SN) hearing loss may be normal even if a significant SN hearing loss is present (1)
• when there is suspicion of hearing loss, audiometry should be performed even if bedside tests are normal

Reference:

• (1) Correspondence to article: D. F. Boatman, et al. How accurate are bedside hearing tests? Neurology 2007; 68: 1311-1314