Hearing loss can occur at any stage of life for a variety of reasons. For example, short term hearing loss can be caused by a common ear infection, which often resolves with treatment and time, while permanent hearing loss will afflict many of us as we grow older. In general, hearing loss can be classified into three types (Weber, 2022; Wahid, Hogan & Attia, 2022):

• Sensorineural: the sound-transducing system that involves the inner ear, cochlea, and auditory nerve.
• Conductive: caused by factors that limit the amount of sound that enters the inner ear such as ear wax buildup or middle ear fluid.
• Mixed loss: is a combination of both conductive and sensorineural hearing loss.

Hearing loss is initially evaluated on routine physical examination using simple tools such as the whispered voice test, otoscopes, and tuning forks. Two quick and easy tests, used in conjunction, that can further distinguish between the different types of hearing loss are the Weber and Rinne tests.

Weber Test (Wahid, Hogan & Attia, 2022; Weber, 2022)

Normally, we hear equally in both ears. The Weber test is primarily used to assess patients with unilateral hearing loss and to characterize conductive versus sensorineural loss.

• Using a 512-Hz tuning fork, strike the tines on your forearm just in front of your elbow and place the stem of the fork on the top of the head or midline of the forehead. Other sites such as the chin or bridge of nose, are sometimes used. The vibrations travel through the skull to the cochlea.
• Ask the patient “Is the sound louder in your right ear, left ear, or the same on both sides?”.
• Results:
  • Normal hearing is confirmed when the sound is heard midline and equally on both sides.
  • Unilateral sensorineural hearing loss is observed if the patient hears the sound louder (lateralizes) in the unaffected or “good” ear.
  • Unilateral conductive hearing loss is observed if the patient hears the sound louder (lateralizes) in the affected or “bad” ear.
  • Symmetrical conductive hearing loss is observed if the patient does not exhibit lateralization.

Rinne Test (Kong & Fowler, 2022; Weber, 2022)

The Rinne test helps to discerns sound transmitted through air versus sound transmitted through bone. This comparison also helps to assess unilateral hearing loss.

• Using a 512-Hz tuning fork, strike the tines on your forearm just in front of your elbow and place the stem of the fork on the mastoid bone behind the ear.
• Ask the patient to cover the other ear with their hand and to report when the sound can no longer be heard.
• When the patient can no longer hear the vibration on the mastoid process, move the vibrating tuning fork near the external auditory canal and ask the patient to tell you when the sound can no longer be heard.
• Results:
  • Normal result is observed when the vibrating fork positioned near the ear is louder and lasts twice as long than when placed on the mastoid bone (i.e., air conduction is better than bone conduction).
  • Abnormal result is observed when sound is at least equally loud or louder when the fork is placed on the bone compared to when it is held next to the ear (i.e., bone is better than air conduction).

Analyzing Results of the Weber and Rinne Tests Together (Weber, 2022)

Together, the Weber and Rinne tests can help determine if the patient’s hearing loss is conductive or sensorineural in nature.

• An abnormal Rinne test (bone is better than air conduction) may indicate conductive loss if the Weber test also lateralizes to that side.
• If the Weber test lateralizes to an ear in which the Rinne test is normal, perform the Rinne test in the opposite ear. A normal Rinne test in the contralateral ear may indicate sensorineural hearing loss. The patient should then be referred for audiogram testing.

PEARLS (Kong & Fowler, 2022; Wahid, Hogan & Attia, 2022; Weber, 2022)

• Unilateral conductive hearing loss may indicate external or middle ear disease.
• Gradual unilateral sensorineural hearing loss may indicate an inner ear disorder (i.e., Ménière disease or an acoustic neuroma).
• The Weber and Rinne tests should not be used as screening evaluations for hearing loss however they can be used to confirm audiometric findings, particularly if audiogram results conflict with clinical findings.
• 512-Hz tuning forks are the preferred tool for assessing hearing loss as they provide the best balance of tone and vibration. Lower frequency (256-Hz and 128-Hz) tuning forks are commonly used in neurological exams as they provide better vibration.

References
 
Kong, E.L. & Fowler, J.B. (2022, February 2). Rinne test. StatPearls [Internet]. National Library of Medicine, National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/books/NBK431071/
 
Wahid, N.B., Hogan, C.J. & Attia, M. (2022, September 14). Weber test. StatePearls [Internet]. National Library of Medicine, National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/books/NBK526135/
 
Weber, P.C. (2022, March 30). Evaluation of hearing loss in adults. UpToDate.
https://www.uptodate.com/contents/evaluation-of-hearing-loss-in-adults