1. Routine Clinical Tests of Hearing
Dr. Krishna Koirala

2. Assessment of Hearing is an integral part of ENT examination
Hearing tests can be divided into subjective and objective tests
Subjective tests like finger friction test , watch test and voice test (whisper/conversation/ loud voice) lack standardization and have become obsolete
Although subjective, tuning fork tests are considered standard tests of hearing evaluation in current clinical practice

3. Aims of Clinical tests of Hearing
Estimation of hearing threshold
Confirm Hearing Loss
Differentiate type of Hearing Loss (Conductive / Sensorineural )
Identification of non- organic hearing loss (Malingerers)

4. Tuning Forks (Gardiner Brown)

5. Different Tuning Fork frequencies used in ENT
256, 512, 1024 Hz
128 Hz produces more vibration sense
>1024 Hz  short tone decay time

6. 512 Hz Tuning Fork is ideal in ENT
No false vibration sensation
Optimum tone decay time
Lies in speech frequency range

7. Striking Surfaces Hard: Olecranon, radial styloid process, patella
Soft: Thenar & hypothenar eminences,
Thick rubber pad
Tuning fork is allowed to fall by its own weight
Impact area is between proximal two-thirds & distal one-thirds of its prongs

9. Tuning fork Tests Routine Tests Rinne test Weber test
Pomroy’s test (ABC )
Schwabach’s test
Others
Bing test
Gelle’s test
Stenger’s test
Chimani Moo’s test

10. Rinne Test
1) Duration comparison technique Vibrating tuning fork placed on pt's mastoid  Patient signals when sound ceases → Move vibrating tuning fork over opening of ear canal (2 cm away & axis parallel to it) → Patient indicates if sound is still heard

11. 2) Loudness comparison technique Vibrating tuning fork placed on pt's mastoid  Pt signals if sound is heard → Move vibrating tuning fork immediately over opening of ear canal → If sound is heard → patient asked to tell which sound is louder?

12. Rinne Test

14. Results of Rinne Test A.C. > B.C. (positive test)
Normal hearing or Sensorineural deafness
B.C. > A.C. (negative test)
Conductive deafness

15. Rinne Negative with different frequency Tuning forks
256 Hz  dB HL (Mild conductive Loss)
512 Hz  dB HL ( Moderate conductive Loss)
1024 Hz  dB HL (Severe conductive Loss)

16. Weber Test
Procedure:
Vibrating 256/ 512 Hz tuning fork placed in midline of pt’s skull at forehead / vertex / central incisor

17. Results of Weber test
Sound heard equally (central) : Normal hearing or B/L equal deafness
Sound lateralizes to deafer ear : Conductive deafness
Sound lateralizes to better hearing ear : Sensorineural deafness

18. Why does Weber lateralize to deafer ear in Conductive Hearing Loss ?
1. Lack of masking effect of surrounding noise on tuning fork sound, as air conduction is reduced in conductive deafness 2. Lack of dispersion of sound energy due to ossicular break

19. Absolute Bone Conduction Test (ABC)
Pt's B.C. is compared with normal examiner's B.C.
Vibrating tuning fork placed on pt's mastoid with pt’s E.A.C. occluded (to prevent A.C.) → pt signals when sound ceases → vibrating tuning fork placed on examiner's mastoid with examiner's E.A.C. occluded

21. Results of Absolute Bone Conduction Test
Pt stops hearing before examiner : Sensorineural deafness
Both hear for same duration : Normal hearing / conductive deafness

22. Schwabach's Test Same as A.B.C. but E.A.C. is not occluded
Pt stops hearing before examiner
Sensorineural deafness
Both hear for same duration
Normal hearing
Pt hears longer than examiner
Conductive deafness

23. Schwabach Test

24. False Negative Rinne
Etiology: Unilateral severe/profound sensorineural deafness
Detection: Rinne negative (No response near the canal), Weber lateralized to better hearing ear
Confirmation: A.B.C. reduced in deaf ear
Correction: Repeat Rinne test with masking of better ear with Barany's noise box

25. Mechanism of false negative Rinne
In deaf ear, air conduction & bone conduction are absent. Trans - cranial transmission of sound to opposite cochlea is perceived as ipsilateral bone conduction. Reported as bone conduction > air conduction in deaf ear (Rinne Negative)

26. Gelle Test
Vibrating tuning fork placed on pt's mastoid & examiner increases pt's E.A.C. pressure with Siegel's speculum
Softer sound
Normal hearing or Sensorineural deafness
No change in sound
Conductive deafness

27. Bing Test
Vibrating tuning fork placed on pt's mastoid & examiner blocks pt's E.A.C.
Louder sound: normal hearing or Sensorineural deafness
No change in sound: conductive deafness