Normal hearing

Conductive HL

Sensorineural HL

Mixed HL

Outer ear Middle ear Inner ear Auditory nerve

Outer ear Middle ear Inner ear Auditory nerve

Outer ear Middle ear Inner ear Auditory nerve

Outer ear Middle ear Inner ear Auditory nerve

CONDUCTIVE SENSORINEURAL

AC √, BC √

AC X, BC √

AC X, BC X

AC X, BC X

Diagnostic tuning fork testsDiagnostic tuning fork tests

1.1. Schwabach (Dabobert Schwabach, 1846-Schwabach (Dabobert Schwabach, 1846-1920)1920)

2.2. Rinne (Heinrich Rinne, 1819-1868)Rinne (Heinrich Rinne, 1819-1868)

3.3. Bing (Albert Bing, 1844-1922)Bing (Albert Bing, 1844-1922)

4.4. Weber (1832-1891)Weber (1832-1891)

The Schwabach testThe Schwabach test

Bone conduction testBone conduction test

Place tuning fork alternatively on mastoid process of patient Place tuning fork alternatively on mastoid process of patient and tester and tester

Is sound heard or not?Is sound heard or not?

Results: Results:

Normal Schwabach: Both stop hearing at the same timeNormal Schwabach: Both stop hearing at the same time

Diminished Schwabach: SN hearing lossDiminished Schwabach: SN hearing loss

Prolonged Schwabach: Conductive hearing lossProlonged Schwabach: Conductive hearing loss

False normal Schwabach: Response to better ear, not test False normal Schwabach: Response to better ear, not test earear

The Rinne testThe Rinne test

Compare hearing sensitivity with AC to that with Compare hearing sensitivity with AC to that with BCBC

Results: Results:

Positive Rinne: Normal hearing or SN hearing Positive Rinne: Normal hearing or SN hearing lossloss

Negative Rinne: Conductive hearing lossNegative Rinne: Conductive hearing loss

False negative Rinne: Non-test ear respondsFalse negative Rinne: Non-test ear responds

The Bing testThe Bing test

Based on the ‘occlusion effect’: If hearing is normal, Based on the ‘occlusion effect’: If hearing is normal, loudness of BC tone increases when ear canal is closed. loudness of BC tone increases when ear canal is closed.

Tuning fork held to mastoid process of patient while ear Tuning fork held to mastoid process of patient while ear canal is alternatively closed and opened by tester. canal is alternatively closed and opened by tester.

ResultsResults

Positive Bing: Sound alternates in loudness. Normal Positive Bing: Sound alternates in loudness. Normal hearing and SN hearing losshearing and SN hearing loss

Negative Bing: No change in loudness. Conductive Negative Bing: No change in loudness. Conductive hearing losshearing loss

False positive BingFalse positive Bing

The Weber test (1834)The Weber test (1834) Based on ‘lateralization’.Based on ‘lateralization’.

Tuning fork placed on the midline of the skull.Tuning fork placed on the midline of the skull.

Where is the sound heard? Left, Right, Both ears, or midline?Where is the sound heard? Left, Right, Both ears, or midline?

ResultsResults

Normal or bilateral symmetrical hearing loss: Midline or in Normal or bilateral symmetrical hearing loss: Midline or in both earsboth ears

Unilateral SN hearing loss: In better earUnilateral SN hearing loss: In better ear

Unilateral conductive hearing loss: In poorer earUnilateral conductive hearing loss: In poorer ear