Subjective Hearing Assessment: Pure-Tone and Speech Audiometry

Question 1

Testing on adults and school-aged children

Answer 1

SUBJECTIVE (behavioral) testing
Complete audiometric examination:
Case history
Otoscopy
Pure tone testing air conduction (right/left)
Pure tone testing bone conduction (right/left)
Speech audiometry
Spondee/speech reception THRESHOLD (dB level): SRT
Word recognition score (percentage): WRS (sometimes called “discrim”)

Tympanometry
Acoustic reflexes

Question 2

Audiometer

Answer 2

Device used to determine hearing thresholds that generates the pure-tone
signals of various frequencies as well as masking noise and speech
Calibrated regularly by a qualified professional to ensure that output is equivalent to a known standard

Question 3

TWO TYPES OF audiometer

Answer 3

Clinical: used for behavioral audiometric assessment
Screening: used for screening (pure-tone stimuli only)

Question 4

Two main components of Audiometer

Answer 4

Oscillator: generates pure-tone stimuli
Attenuator: controls intensity of stimuli presented

Question 5

Oscillator

Answer 5

generates pure-tone stimuli

Question 6

Attenuator:

Answer 6

controls intensity of stimuli presented

Question 7

Different stimuli used with audiometer

Answer 7

Pure tones: 125Hz-12kHz (250-8000Hz)
Speech

Question 8

Different transducers used
with audiometer

Answer 8

Headphone: two types
Supra-aural
Insert
Bone oscillator
Loudspeakers (for soundfield testing)

Question 9

Sound-Treated Audiometric Booth

Answer 9

Two layers of metal panels for walls, with holes in walls for cables

Thick metal double doors close tightly to prevent sounds from leaking in
Incandescent (rather than fluorescent) lights used to reduce ambient noise level

Ventilation with sound attenuation
Raised floor is carpeted
No windows (except between audiologist and patient)

Question 10

Case history obtains the following

Answer 10

Pertinent identifying information
Nature of past and present hearing problems
Other medical problems
Prior use of amplification

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For children, additional information includes
Details about mother’s pregnancy and the child’s birth
Development of gross and fine motor skills, development of speech and language
Childhood diseases

Question 11

Otoscopy

Answer 11

Otoscopy: inspection of the pinna and EAM using an otoscope for the presence of
outer ear malformation/earpits/tags
foreign bodies
occluding cerumen
signs of inflammation/irritation
blood/pus/scarring/dried blood

Appearance of TM also noted
Normal TM is gray/translucent with manubrium visible
ME disease may be suspected if
TM bulging or distended or opaque
Fluid is visible in ME space, or
Scars, perforations, and/or tears are present

Question 12

Air conducti

Answer 12

Air conduction: threshold obtained using headphones (supra-aural or insert)
Degree of hearing sensitivity determined
Slight, mild, moderate, moderately-severe, severe, profound
Tests outer, middle, and inner ear

Question 13

Bone conduction:

Answer 13

: threshold obtained with bone oscillator
Type of hearing loss determined
Conductive, sensorineural, mixed
Thresholds reflect function of cochlea/inner ear only (outer- and middle-ear function bypassed)

Question 14

Air Conduction Assessment

Answer 14

Start at 40 dB HL
Use staircase method (down 10 dB/up 5 dB strategy) to determine threshold
Watch this YouTube video:

Question 15

Frequencies tested with air conduction

Answer 15

Typically, octave frequencies of 250, 500, 1000, 2000, 4000, 8000 Hz assessed
Interoctave frequencies of 750, 1500, 3000, and 6000 may also be assessed
Tested if there is a 15-dB difference between two octave frequencies or if patient is considering amplification

Question 16

Patient Response

Answer 16

Instructions given to patient when tone is heard
Audiologist should avoid inadvertently giving cues
Raise hand
Press response button
Vocal response (“yes”)

Question 17

False Responses

Answer 17

False negative: no response when one is required
False positive: response when no stimulus is presented

Question 18

Bone Conduction Assessment

Answer 18

Signals via bone oscillator (usually placed on the mastoid process of the temporal bone )

The pure tone directly stimulates the cochlea, bypassing the outer ear and middle ear systems

If air conduction shows a reduction in hearing sensitivity but bone conduction shows normal sensitivity, the impairment probably results from an obstruction of the outer or middle ear (conductive hearing loss)
If air- and bone-conduction thresholds are similar, a sensorineural hearing loss is presumed

Question 19

Normal hearing

Answer 19

Bone and Air conduction are the same

Question 20

Conductive hearing lost

Answer 20

bone conduction results are
normal and air conduction is bad

Question 21

sensorineural hearing lost

Answer 21

Air and bone conduction are bad at equal amount

Question 22

mixed hearing lost

Answer 22

Bone is poor and air is even poorer:

Question 23

Bone Conduction Assessment Continuation

Answer 23

Start at 40 dB HL
Use staircase strategy (down 10 dB/up 5 dB) (same as air conduction assessment)
Frequencies tested: 500, 1000, 2000, 4000 Hz
Interoctave frequencies tested if assessed during A/C up to 6000 Hz
Recording
< threshold of right ear (unmasked)
> threshold of left ear (unmasked)
[ threshold of right ear (masked)
] threshold of left ear (masked)

Question 24

Air–Bone Gap

Answer 24

Difference between A/C and B/C thresholds at a given frequency

Air–bone gaps ≥15 dB represent a significant conductive hearing loss in adults
In pediatric clients, more conservative air–bone gap of ≥10 dB HL is used
May require medical referral, even if the A/C thresholds are ≤25 dB HL at all frequencies

When A/C and B/C thresholds are approximately the same at all test frequencies, this suggests a sensorineural loss

Question 25

Mixed Hearing Loss cont

Answer 25

When both A/C and B/C thresholds are reduced in sensitivity, but B/C testing yields better results than A/C testing The patient’s hearing loss is partially conductive and partially sensorineural

Question 26

Masking

Answer 26

The process by which the threshold of a stimulus is elevated by the simultaneous introduction of another sound Used whenever there is a possibility of cross-hearing, which is the reception of a sound signal during a hearing test (either by A/C or B/C) at the ear opposite the ear under assessment When masking is used Air conduction testing Both pure-tone and speech assessments Bone conduction measurements

Question 27

Masking cont

Answer 27

Sound (typically frequency-specific narrowband noise) presented to the non-test ear to prevent it from perceiving the test signal presented to the test ear

Question 28

Cross hearing:

Answer 28

contralateralization of the test signal (crosses to opposite ear)

Question 29

Interaural attenuation

Answer 29

Interaural attenuation: the loss of energy of a sound presented either by A/C or B/C as it travels from the test ear to the non-test ear (aka crossover levels) Air conduction: depends on transducer used Supra-aural phones = 40 dB HL Insert phones = 70 dB HL Bone conduction = 0 dB HL

Question 30

Rationale for Speech Audiometry

Answer 30

Main goal: to quantify a patient’s ability to understand everyday communication Why? We don’t speak in pure tones, nor do we speak at threshold levels A basic tool in the overall assessment of hearing handicap Other goals in speech audiometry Check validity of pure-tone audiometry Determine reference for suprathreshold testing Assessment of amplification or rehabilitation Estimate degree of communicative function Monitor progress in aural rehabilitation

Question 31

Calibrated amplifying system Inputs

Answer 31

microphone, tape recorder, CD player

Question 32

Calibrated amplifying system outputs

Answer 32

earphones, bone oscillator, loudspeaker in the test room

Question 33

Clinical Decisions in Speech Audiometry

Answer 33

Mode of test presentation Voice (monitored live voice, MLV) Tape/CD (preferred mode of presentation) Mode of response Voice Written (i.e., forced choice) Sign language Listening conditions Masking

Question 34

Speech reception threshold

Answer 34

Speech reception threshold (SRT): lowest intensity at which a person can identify simple speech materials approximately 50% of the time

Question 35

Assessment of Speech Threshold

Answer 35

Speech reception threshold (SRT): lowest intensity at which a person can identify simple speech materials approximately 50% of the time Obtain threshold for speech in dB HL Staircase method used (as in AC and BC) Word lists: spondaic words (spondees) Spondee: two-syllable words with equal emphasis on each syllable; low-frequency-dominant sounds

Question 36

Word recognition score (WRS)

Answer 36

Word recognition score (WRS) Also called speech discrimination score (SDS) or word discrimination score (WDS) Phonetically balanced (PB) monosyllabic word lists

Question 37

Assessment of Suprathreshold Speech Recognition

Answer 37

Word recognition score (WRS) Also called speech discrimination score (SDS) or word discrimination score (WDS) Phonetically balanced (PB) monosyllabic word lists Multiple-choice tests (e.g., California Consonant Test) Sentence tests

Question 38

Assessment of Suprathreshold Speech Recognition cont

Answer 38

Obtain score in % correct Either 50 words (full list) or 25 words (half list) used Method to determine WRS More often than not, present at 35 dB above SRT Determine “MCL” most comfortable listening level

Question 39

Word Recognition Score List

Answer 39

Carrier phrase: “Say the word…” (VU meter) In order of difficulty mew, bathe, felt, ache, knees, twins, thing, stove, true, skin as, she, or, it, jam, me, there, aisle, them, wet, could, toe, not, up, you Phonemically balanced

Question 40

Word Recognition Scores cont

Answer 40

88-100%: EXCELLENT 72-84%: GOOD 60-68%: FAIR Below 60%: POOR

Question 41

Uncomfortable loudness level (UCL) and most comfortable loudness level (MCL)

Answer 41

Uncomfortable loudness level (UCL) and most comfortable loudness level (MCL) Both suprathreshold levels are determined in dB HL Method to determine each level Dynamic range: the difference between UCL and SRT Example: UCL = 110 dB HL; SRT = 10 dB HL Dynamic range in this case equals 100 dB

Question 42

Speech-in-competition measures

Answer 42

Speech-in-competition measures Sentence recognition tests Synthetic Sentence Identification (SSI) Speech-in-noise (SPIN) test Staggered Spondaic Word (SSW) test Ling 6-sound test /a/, /u/, /i/, /m/, /sh/, /s/ Measured as number correct

Question 43

Issues in Speech Audiometry

Answer 43

Masking to avoid cross hearing Recommended whenever speech audiometry is assessed Testing non-native speakers of English Numerous word lists available for purchase in Spanish, Portuguese, Italian, French, Tagalog, Polish, Russian (just to name a few languages)