Rinne Test

Original Editor - Mohamed A Hassanin
Top Contributors - Mohamed A Hassanin and Rachael Lowe

Introduction

Hearing deficiency or loss is a major sensory impairment affecting the auditory system, it can be unilateral or bilateral. Also, it can be caused by various factors that may be age-related, immune- related or genetic or psychological or related to other factors. These causes may affect the delivery of sound waves to the inner ear (conductive hearing loss) due to diseases or deficits in the middle ear, ear canal or pinna (external meatus) or may affect the inner ear itself or its neural structures (CN VIII) known as sensorineural hearing loss.

Purpose

This test is one of the clinical examination bullets to assess the unilateral conductive hearing loss. It is also applied together with Weber test to differentiate conductive from sensorineural hearing loss types.

Technique

Human cochlea (one of the structures of the inner ear) can receive sounds either from the usual way which is ear canal and middle ear (air conduction) or through the rare way which is bony conduction due to its location inside bone cavity related to the skull. Normally, the air conduction is more clear or louder than bony conduction. Rinne test examines this fact through the following steps:

1. The fork is vibrating and placed on the mastoid process (bone conduction) while the patient is informed to say when sounds of vibrations stopped.
2. The vibrating fork is relocated in front of but 1 cm away from the same side ear pinna (may be up to 3 cm) and the patient clarify the moment of hearing stoppage.
3. The test is positive when sounds by air conduction is heard longer. However, it is considered negative when sounds by bone conduction is heard longer.

False Negative Rinne test (False conductive hearing loss) appears when person has complete deafness in one ear and the test result is sounds heard longer by bone conduction this is due to the fact that bone conduction delivers the sounds to both cochleae so the other intact cochlea can hear sounds. This is one reason to apply Rinne test with Weber Test.

Evidence

For a 256-Hz fork, the sensitivity of Rinne test was ranged (43% - 91%) and specificity ranged (50% - 100%). Meanwhile, they ranged from 16% to 87% and from 55% to 100% respectively for a 512-Hz fork.