This ppt is about pure tone audiometry which is a subjective audiological procedure done in ENT to assess hearing loss and its degree

1. PURE TONE
AUDIOMETRY
SRUTHI LAKSHMANAN
RA1841002010134

2. AUDIOMETRIC TESTS
• SUBJECTIVE TESTS
TUNING FORK TESTS
PURE TONE AUDIOMETRY
BEHAVIOURAL OBSERVATION
AUDIOMETRY
SPEECH AUDIOMETRY
• OBJECTIVE TESTS
TYMPANOMETRY
AUDITORY BRAINSTEM
RESPONSE
OTOACOUSTIC EMISSION

3. PRINCIPLE
• PURE TONE AUDIOMETRY IS A SUBJECTIVE
AUDIOLOGICAL PROCEDURE TO MEASURE HEARING ACUITY
USING PURE TONES BOTH QUALITATIVELY AND
QUANTITATIVELY.
• SERIES OF SOUNDS AT VARIOUS FREQUENCIES ARE
PRESENTED TO MEASURE THE INTENSITY AT WHICH SOUND
IS HEARD AND DEGREE OF DEAFNESS.

4. PROCEDURE
• PERFORMED IN SOUNDPROOF OR QUITE ROOM.
• INITIALLY AIR CONDUCTION OF BOTH EAR IS
RECORDED FOLLOWED BY BONE CONDUCTION.
• SOUNDS ARE TESTED IN FREQUENCY RANGE OF 125-8000 HZ.
• FOR EACH FREQUENCY, INTENSITY OF SOUND IS GRADUALLY INCREASED
TILL SUBJECT EASILY HEAR IT AND, THEN, SLOWLY DECREASES TILL SUBJECT
CAN NO LONGER HEAR.
• INTENSITY AT WHICH SUBJECT HEARS SOUND IS TAKEN AS THRESHOLD OF
HEARING AT THAT FREQUENCY.
• FINDINGS OF PURE-TONE AUDIOMETRY ARE PLOTTED ON A CHART CALLED

5. Right ear-
RED
Left ear-BLUE

6. DEGREE OF HEARING LOSS IN AUDIOGRAM

7. CONDUCTIVE DEAFNESS
BONE CONDUCTION
THRESHOLD
AIR CONDUCTION
THRESHOLD
AIR-BONE
GAP
(NORMAL
)
(ELEVATED)
(MORE THAN 15 dB)

8. AUDIOGRAM IN OTOSCLEROSIS
CAHART’
S NOTCH

9. SENSORINEURAL HEARING LOSS
BONE
CONDUCTION
THRESHOLD
AIR
CONDUCTION
THRESHOLD
(ELEVATED)
(ELEVATED)
NO AIR-BONE
GAP

10. AUDIOGRAMS
BILATERAL SLOPING CURVE
IN
DIP AT 4000Hz-ENVOTO
NOTCH

11. RISING TYPE
FLAT TYPE
FALLING
TYPE
(In early stages when
low frequencies are
affected)
(In late stages, when
high frequencies are
affected)

12. MIXED HEARING LOSS
BONE
CONDUCTION
THRESHOLD
AIR
CONDUCTION
THRESHOLD
AIR-BONE
GAP
(ELEVATED)
(ELEVATED)

13. *ADVANTAGES
• TESTING OF VARIOUS
FREQUENCIES
• GIVE IDEA ABOUT BOTH TYPE
OF HEARING LOSS
{QUALITATIVE) AND DEGREE OF
HEARING LOSS {QUANTITATIVE)
• DOCUMENTATION FOR FUTURE
REFERENCE
• CAN PROVIDE BASELINE FOR
VARIOUS RECONSTRUCTIVE
AND REHABILITATIVE
PROCEDURES
• TO COMPARE SERIAL
DISADVANTAGES
• SUBJECTIVE TEST
• REQUIRES PATIENT ABLE TO
UNDERSTAND INSTRUCTIONS
• CANNOT DETECT
MALINGERING
• MASKING NEEDS TO BE DONE
TO AVOID INVOLVEMENT OF
NON-TEST EAR

14. APPLICATIONS
• MEASURES THRESHOLD OF HEARING BY AIR AND BONE
CONDUCTION AND, THUS, DEGREE OF TYPE OF HEARING LOSS
• A RECORD CAN BE KEPT FOR FUTURE REFERENCE
• ESSENTIAL FOR PRESCRIPTION OF HEARING AID
• HELPS TO FIND DEGREE OF HANDICAP FOR MEDICOLEGAL
PURPOSE
• HELPS TO PREDICT SPEECH RECEPTION THRESHOLD

15. DIAGNOSIS FINDINGS
NORMAL THRESHOLD BETWEEN 0-20 dB
CONDUCTIVE
DEAFNESS
Reduced air conduction and normal bone
conduction, i.e. air-bone or AB gap
present
SENSORINEURAL
DEAFNESS
Reduced air conduct ion and bone
conduction
Deafness more severe in higher
frequencies
MIXED DEAFNESS Reduced air conduction, partially
reduced bone conduction
SUMMARY