short notes about hearing and audiological assessments

1. Dr. Yasien Alghzuy
Audiovestibular consultant
Alhaboobi audiovestibular center
BASIC
AUDIOLOGICAL
ASSESSMENTS

2. What is an Audiological Evaluation?
 An audiological evaluation is a series of tests called as (Audiological test
battery ) use to determine the type, degree and configuration of hearing
loss. The tests often provide insights on what the causes of hearing loss. And
we can use the information and results to develop a treatment plan that will
be most effective to each diagnosis
 An audiological evaluation may be performed by an audiologist or
Audilovestibular specialist
 Audiological evaluation best performed according to the age of
patients ,social and medical conditions of patients availability of equipment's
, & experience of medical & technical staff

3. Terminology
 Hearing loss is a medical term that refers to degree of patients hearing difficulty
measured by dBHL
 Hearing impaired is public term used to describe people with any degree of
hearing loss, from mild to profound, including those who are deaf and those who
are hard of hearing.
 Hearing disability refers to hearing loss greater than (35dB) in the better
hearing ear
 Frequency sometimes referred to as pitch, is the number of times per second
that a sound pressure wave repeats itself (F = cycles / time ) Hz
http://www.hearingloss.org/

4.  Sound intensity (loudness ) is defined as the sound power per unit area . whereas
amplitude is the distance between the resting position and the crest of a wave. Unite
of intensity in general is the but sound intensity use the (deciBel) dB HL or SPL

5. =
10
log = dB
×
Io
dB
I= specific sound intensity
Io= reference intensity
= 𝑊 /𝑀2
=
10
log
=
10
log (10)
=
10
×
1
=
20
dB
For example sound level
𝑊 /𝑀2 dB
SPL
??
𝒅𝑩(𝑩𝒂𝒔𝒄𝒂𝒍)𝑾 / 𝑴𝟐
50dB SPL
×
Io
I
=
𝑾 / 𝑴𝟐
𝑊 /𝑀2
𝑊 /𝑀2
=
10
log
=
10
log
/
10
=
log
10
=
𝑊 /𝑀2
𝑊 /𝑀2
??
=
1OOO
Log (1000)=3

6. Audiological Assessments
Subjective tests
 Subjective audiometry tests
depending on the subjective
responses from the patients to
various sound stimuli. That
make the patient have a roll in
the test results
 Pure tone audiometry
 Speech Audiometry
Objective
 Objective audiometry tests measures the
electrical activity in the auditory pathway. It
does not require a patient to participate.
And haven't rol in the test results
 Impedance Audiometry (Tympanometry ,
acoustics reflexes ,reflex decay & ETF )
 OAE (TE OAE ,DP OAE )
 ABR / ASSR
 EchoG

7. Pure Tone Audiometry
 Subjective test measure the acuity of hearing threshold of an individual
by instrument known as the audiometer.
 Hearing threshold : is the lowest level of sound where the patient can hear
in 50% of times For each specific frequency .
1. To know whether the subject has any definitive H.L.
2. To know the types of H.L( conductive , mixed or
sensorineural ( cochlear or retro-cochlear ) by use special
tests ( SISI ,ABLB ,Stenger )
3.To determine The degree of hearing dysfunctions (mild –
moderate – sever or profound )
4. To show the configuration of hearing loss curve
The aims of PTA

8. Diagnostic standard audiometer
2 channals ( masking )
AC Freg :125 Hz - 12KHz
Intensity -10 -120 dBHL
BC : -10 -80 dBHL
screening audiometer
AC , one intensity ,3
frequencies ,pass or failed
Computer based audiometer
AUDIOMETER TYPES
Play audiometer/VRA

9. Tranceducers & basic compenants
Supra-aural:TDH-39
Circumaural:HDA200
bone oscillator B71 . B81
Inserted:ER
Loudspeakers
Diagnostic PTA
AC Conduction
BC Conduction Free field test & S. Aud
.
Freq selector dial
Intensity selector dial
Tone presentation switch
Output selector
Earphone AC, L&R ear
Masking on /off
Microphone
IAA 55dB IAA 0dB
IAA 45dB
IAA 40dB

10.  Sound attenuating room
 Single or double walled ,4 inch thick
 Inside wall covered with sound absorbed material ,
small holes to absorb sound to decrease
reflection .
 Patient positioned :-
 45 -90 degree :
 away from the examiner for adult
 And away from the speaker in case of visually
reinforcement Audiometry in children .
 Face the speaker :
 patient with hearing aid To ensure that the sound is
directed to the microphone of the hearing aid
The test Environment

11.  Calibration should involves calibration of audiometer, earphones and bone
vibrators , Can be performed using human volunteers and artificial ears
 Malingerer’s should be tested only by an audiologist
 Short brief history & rapid local examination
 Otoscopy & Tympanometry should be done prior to audiometry
 Test procedure should be fully explained to the patient
 Glasses / ear rings should be removed
 start with the better ear or the right ear
 Red headphone is placed over right ear
 BiL AC before BiL BC
Before testing
-:

12. 06/16/2025 12
The Audiogram
AC
BC
Masked
Unmasked
AC
BC RT-Ear
LT-Ear

13. 06/16/2025 13
Hearing Level HL ??
 Human hearing varies according to
the frequency of the sound
 At 1000 Hz the weakest sound a
normal-hearing person can hear is
7.0 dB SPL 1000 Hz
 At 4000 Hz the normal threshold is
12.0 dB SPL becomes 0 dB HL at 0
dB HL at 4000 Hz
 The relationship between HL and
SPL is defined by ANSI S3.6-1996.
 Each of these SPLs becomes 0 dB
HL at the test frequency.
Reference Equivalent Threshold Sound Pressure Levels
0
5
10
15
20
25
30
35
40
45
50
125 250 500 750 1000 1500 2000 3000 4000 6000 8000
Frequency (Hz)
S
o
u
n
d
P
re
s
s
u
re
L
e
v
e
l
(d
B
)
dBSPL
dBHL
SPL= (HL) X (RE SPL) / 10 AT 1000Hz
SPL= 50db HL X 7/10
=
SPL = 350 / 10 = 35 dBSPL
HL = SPL / (RE spl ) X 10 AT 500Hz
HL = 40 / 15 X 1O
HL = 2.6 X 10 = 26 dBHL
?
?

14. HOW READING AUDIOGRAM ?
1
-
Identification
2
-
PTA notes ( IAA , A/B gap
indication of masking
3
-
Response Consistency
(good ,intermediat ,poor )
4
-
Validity of test(reliable or
questionable )
5
-
PT Average
,
6
-
Degree of hearing loss
7
-
Type of hearing loss
.
8
-
Configuration of PTA
9
-
Report or comments
.
Steps of PTA reading
-:
Direction ,degree ,type , configuration , notes ,recommendation

15. 2- PTA notes ( IAA , A/B gap ) indication of masking
Masked
Unmasked
Lt HT = 65 dB
Lt HT = 50 dB
SNHL
Mixed HL

16. 3,4- Response consistency & validity of the test:-
 Poor: many false negative & false positive responses.
 Intermediate : moderate amounts of false negative & positive responses.
 Good : no or minimum amounts
False +ve : no stimulus , response present.
False –ve : suprathreshold stimulus ,no response
 validity of the test ( reliable results or questionable )
 Subsequent test results should vary not more than 5dB .

17. 5dB 10
dB 500Hz
20
dB 15
dB 1kHz
25
dB 20dB 2
KH
40
dB 30
dB 4
KH
PTA AVG (500 – 4000Hz) in dB
Best binaural to
correlate with FFT
or SDT
LT-HT(dBHL) R-HT (dBHL)
13 13 15 Three freq
23 22 18 Four freq
17
06/16/2025
Freq. Rt-Ear Lt-ear
5-PT Average ?

18. 6- Good's Man Classification for Degree of HL
 -10 to 15 dB normal.
 16 to 25 dB slightly HL
 26 to 40 dB mild.HL
 41 to 55 dB moderate.HL
 56 to 70 dB mod-sever.HL
 71 to 85 dB sever.HL
 86 to 90 dB sever profound.HL
 > 91 dB profound HL

19. 7-Types of Hearing Loss
 Conductive Loss ( Abnormal AC , Normal BC ,ABG > 10dB )
 Sensorineural Loss ( Abnormal AC , Abnormal BC ,ABG <10dB )
(Sensory or Neural ? )
 Mixed Hearing Loss ( Abnormal AC , Abormal BC ,ABG > 10dB )
 Normal for speech frequncies (Normal AC& BC For speech Feq. Only )
 Normal with Conductive element. ( Normal AC , Normal BC ,ABG > 10dB )

20. HT=5dB (Normal ) HT=18dB (Normal
with cond.element )
HT=70dB (Mixed HL) HT=65dB (SNHL)
A/B gap > 10 dB
HT=40dB
(Conductive HL)
HT=15dB (Normal for
speech freq.)

21. 8-Configuration of PTA
 Flat <5dB average difference per octave
 Gradually sloping 6-10dB rise or fall per octave
 Sharply sloping 11-15dB rise or fall per octave
 Abruptly sloping ≥16dB rise or fall per octave
 Rising Better hearing at the higher frequencies
 Trough or saucer ≥20dB more loss at middle frequencies than at 250 and
8000Hz
 Notch Sharply poorer at one frequency, with recovery at adjacent frequencies

22. flat
Notch /AT
Abruptly sloping
Sharply sloping
Trough or saucer
Rising/OME
Rising/MD
Gradually sloping
Notch/OS
Corner/tactile

23. Limitation of PTA
 Subjective test
 Improper masking
 Faulty placements of headphones and vibrator
 Occlusion effect during BC
 Noisy environment
 Improper calibration of audiometers
 Improper examiner

24. 24
Speech Audiometry
Comprehension Understanding the meaning
identification Can say what the word is
Discrimination Can tell the difference between words
Detection Can say speech is present
Define as the measurement of patient's ability to hear and understand the
speech
.
 It is complementary to pure tone audiometry ; which only gives an
indication of absolute perceptual thresholds of tonal sound (peripheral
function), whereas speech audiometry determines speech intelligibility
and discrimination .

25. Speech Audiometry
Phonetically balanced word list( monosyllabic words or bisyllabic words ) words
must be covered in patients language.
 Speech Detection Threshold (SDT) = lowest level of speech can be detected at
50% of times (normal = PTA (+/- 10dB )
 Speech reception threshold (SRT) = lowest level of speech can be identified
and repeated corrctyl at 50% of times (Normal <25 dB)
 Speech discrimination score (SDS ) /WRS = percentage of correctly identified
words.
 Normal score is 90 to 100% ,
 Conductive 70-80% ,
 Sensory L 50-60 %
 In neural loss SDS is low. (< 50 % )

26. THE WRS CURVE FOR RETROCOCHLEAR HEARING LOSS
?

27. ROLLOVER INDEX
??
*
It is seen in retro cochlear hearing loss
*
With increase in speech intensity above a particular level, the word
score fall rather than maintain a plateau as in cochlear type of hearing
loss

28. *
If the patient is not a native language speaker, you may
need to skip speech audiometry and note why didn't perform
speech testing on the audiogram
*
If you have hearing loss (as the tester) you may have
difficulty hearing what the patient said
*
Don't be afraid to ask the patient for clarification on a word
or to use the word in a sentence if you aren't sure what
they said
*
Have the patient face you so you can read their lips just
make sure they can't see your lips if you aren't using a
recorded list
)
Limitations of speech audiometry

29. Impedance Audiometry
 1. Tympanometry
 2. Eustachian tube function tests
 3. acoustic stapedial reflex tests

30. 1. Tympanometry

32. 2. Eustachian tube function tests
 Eustachian tube dysfunction is a
condition where the tubes that
connect middle ears to upper throat
become blocked. This can lead to
discomfort, hearing difficulties and a
feeling of fullness in ear.

33. 3. acoustic stapedial reflex tests
 This objective test is to make sure that the stapedius muscle in your middle
ear is functioning correctly and providing a protective mechanism by
stablising the hearing bones of the middle ear by contracting to loud sounds

34. Otoacoustic Emissions (OAE )
 OAE are low-intensity sounds/acoustic signals that
are generated by the cochlea and propogate through
the middle ear into the ear canal where they are
recorded
 OAEs are probably not essential to hearing, but
rather are the byproduct of active processing by the
outer-hair cell system.
 They are most probably generated by active
mechanical contraction of the outer hair cells,
spontaneously or in reponse to sound.
 OAEs reveal, with considerable sensitivity, the
integrity of outer-hair cell function

35. TYPES OF OAE
 Spontaneous otoacoustic emissions (SOAEs) - Sounds emitted without an
acoustic stimulus (ie, spontaneously).
 Transient otoacoustic emissions (TOAEs) or transient evoked otoacoustic
emissions (TEOAEs) - Sounds emitted in response to an acoustic stimuli of very
short duration; usually clicks but can be tone-bursts.
 Distortion product otoacoustic emissions (DPOEs) - Sounds emitted in response
to 2 simultaneous tones of different frequencies.
 Sustained-frequency otoacoustic emissions (SFOAEs) - Sounds emitted in
response to a continuous tone.

36. DPOAE
TEOAE

37. Auditory Brainstem Response (ABR
 A diagnostic Auditory Brainstem Response (ABR) is a test that
looks at neural responses to sound to determine whether lesions
or other abnormalities exist in the ear, along the auditory nerve,
or in the brainstem. Some wires are taped to the patient's scalp
and ears and connected to a computer

38. ABR

39. Hearing assessment in children
The diagnostic test used depend on the child chronological & developmental age
1-Distraction test. (6-8 M.)
2- (Co-operative) test.
Visual Reinforcement Audiometry (VRA) (8-30 M.)
3-Performance test (play conditioning
Audiometry ). ( > 30 M.)
4- F.F. speech discrimination tests..... under 5Y.
4-PTA. > 5 Y
6-Impedance measure.:
7-OAEs.
8-ABR

40. 06/16/2025 40
Reading sources
1- HCHA 101-4 Hearing Evaluation Procedures 21 pages.
2- AUDIOLOGY the fundamentals cha 4 p 101 -131.
3- Old book (Audiometery) papers.
4- Audiology for practice 2 books for how to interpret PTA.
5- Audiology DIAGNOSIS by Ross J.Roeser cha11,page 227-249.
6- Scott- Brown p 3260 -3274)
7-Kramer. S, and Brown, D. (2019)
8- Audiology Science to Practice (

41. 06/16/2025 41
Reading sources
1- HCHA 101-4 Hearing Evaluation Procedures 21 pages.
2- AUDIOLOGY the fundamentals cha 4 p 101 -131.
3- Old book (Audiometery) papers.
4- Audiology for practice 2 books for how to interpret PTA.
5- Audiology DIAGNOSIS by Ross J.Roeser cha11,page 227-249.
6- Scott- Brown p 3260 -3274)
7-Kramer. S, and Brown, D. (2019)
8- Audiology Science to Practice

42. Thanks for Attention
Any questions