The document discusses the history, parts, types, uses and applications of the tuning fork, including how it was invented in 1711 and produces sound notes through vibration; it describes tests like Rinne's test, Weber's test and Schwabach's test that use tuning forks to assess hearing by comparing air and bone conduction between the ears. The tests help determine types of hearing loss like conductive or sensory deafness.

1. TUNING FORK
D r. A N IKET A . SHILWA N T
Assistant Professor
Sharir Kriya Dept.
GJPIASR
CVM UNIVERSITY

2. I N T R O D U C T I O N
 Invention – In 1711 by a British Musician – John Shore
 John Shore – A Trumpeter and a Lutenist in a British Musical Band
 A metal instrument with a handle and two prongs or wings to create sound
notes.
 It is also known as an – Acoustic Resonator
 Pitch of sound notes depends on the length and mass of the two prongs.

3. P R I N C I P L E
 A tuning fork emits a tone or sound notes at a particular pitch.
 The tuning fork is set into vibration by holding the stem or handle in
the hand and stroking the prongs over a firm and resilient surface.

4. P A R T S
 Prongs / Wings
 Stem / Handle
 Base / Foot Plate

5. T Y P E S
 Depends on the frequency of the
sound notes produced –
 128 Hz
 256 Hz
 512 Hz

6. U S E S
 Assessment of Hearing sensation
 Primary assessment of Bone fractures

7. A P P L I C A T I O N S
 Assessment of Hearing sensation can be done by three different tests
–
 Rinne’s Test
 Weber’s Test
 Schwabach’s Test

8. R I N N E ’ s T E S T
Invented by – German otologist Heinrich Adolf Rinne (1819-1868)
Principle – It takes greater level of vibrational stimuli to Bone conduction than Air conduction.
Aim – To determine the conductive hearing deafness of a subject by comparing Air and Bone
conduction.
Procedure –
• Set a tuning fork into vibration. Keep a base of vibrational tuning fork on the mastoid
process at post-auricular region on one side of subject. Start the stop watch simultaneously.
• Ask the subject to indicate the inaudibility of sound notes by raising his/her hand and not the
time period. This is Bone Conduction.
• Later, bring the same tuning fork immediately near to the same sided ear without touching
any part. The sound notes are again audible.

9. R I N N E ’ s T E S T
• Ask the subject to indicate the inaudibility of sound notes by raising his/her hand and not
the time period. This is Air Conduction.
• During this, the non-testing ear should be masked in order to prevent of masking effect
of sound.
Observation –
Total Air conduction = Time period of Bone Conduction + Air conduction
Result interpretation –
• Rinne’s test Positive – Air conduction greater than Bone conduction
• Rinne’s test Negative – Air conduction is less than Bone conduction
Normally, Rinne’s test is always positive with Air conduction always greater than Bone
conduction.

10. R I N N E ’ s T E S T

11. W E B E R ’ s T E S T
Invented by – Ernst Heinnich Weber
Principle – It depends on - The Stenger Principle, which states that a person will only hear the
louder of two identical tones presented to both ears at the same time.
Aim – To determine the unilateral hearing loss (Conductive or Sensory deafness) of a subject
by comparing Bone conduction on both sides simultaneously.
Procedure –
• Set a tuning fork into vibration. Keep a base of vibrational tuning fork in the center of scalp
(midline of head) or in between two eyebrows (Nasion). Start the stop watch simultaneously.
• Ask the subject to indicate the inaudibility of sound notes by raising his/her hands and note
the time period. This is Bone Conduction for weber test.

12. W E B E R ’ s T E S T
Observation –
Note the time period for bone conduction
Also look for raising of both hands simultaneously indicating symmetrical bone conduction.
Conductive deafness – Bone conduction is very clear in the Affected ear itself. This is due to
absence of masking of sound phenomenon.
Sensory or neural deafness – Bone conduction is poor or inaudible due to nerve damage.
Result interpretation –
Symmetrical bone conduction – Weber’s test normal

13. W E B E R ’ s T E S T

14. S C H W A B A C H ’ s T E S T
Principle – It is based on the principle that the examiner should have a normal
hearing, or when the tuning fork is vibrated the sound fades after sometime.
Aim – To assess and compare the bone conduction and hearing sensitivity of a
subject with that of examiner.
Procedure –
Base of a vibrating tuning fork is kept over the mastoid process of the patient. Start
the stop watch simultaneously.
Ask the subject to indicate the inaudibility of sound notes by raising his/her hands
and note the time period. This is Bone Conduction for schwabach’s test.

15. S C H W A B A C H ’ s T E S T
• Later the same vibrating tuning fork is brought and kept on the mastoid process of
examiner immediately.
• Examiner should look for audibility of sound notes, as examiner is standard for that case.
• If both the subject and examiner are normal, then the bone conduction will be same and
examiner will also be unable to hear the sound notes.
Observation –
Note the precise time period of bone conduction for subject and examiner.
Result interpretation –
Symmetrical bone conduction in subject and examiner is indicative that Schwabach’s test is
normal.

16. Thanks!
D r . A n i k e t A . S h i l w a n t
Assistant Professor
Sharir Kriya Dept.
GJPIASR, CVM University
ayuraniket18@gmail.com
aniket.shilwant@cvmu.edu.in
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