Download speech audiometry

PHYSICAL
EXAMINATION
 Examination of the ear and related head and
neck structures should be performed in a
systematic and consistent manner so that
no part of the exam is neglected
EXTERNAL AUDITORY CANAL
(EAC)
 composed of cartilage covered by skin
 outer 1/3 cartilaginous (mobile)
- inner 2/3 bony
 with narrowing at the bone-cartilage junction
(narrowest area)
 skin lining cartilaginous portion is thicker
 Bony portion of the EAC is the only structure
in the body where there is skin directly
overlying bone with no subcutaneous tissue
 area is very sensitive and swelling is very
painful as there is no room for expansion
AURICLE OR PINNA
- A complex cartilaginous structure that is
covered with skin
- Has a variety of folds which are generally
consistent but vary slightly from individual to
individual
- Important to know the embryology of the
auricle in understanding the different
pathological conditions
 Development of the auricle embryologically
is complicated, sometimes resulting in
developmental anomalies including pre
auricular skin tags, and small accessory
auricles
 Cosmetically pleasing auricle is generally
positioned with the concha at a 90 degree
angle lateral to the head
 helix and antihelix must be well formed
 Noticeable differences , even if minor,
between an individuals right and left auricles
are abnormal and should suggest a
pathological process
INSTRUMENTS USED IN DOING
OTOSCOPY
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Penlight
Aural speculum
Otoscope
Appropriate source of illumination –
floor lamp, head mirror, head light
 Ear Examination Instruments
 -penlight - may be used to examine
external ear and ear canal
 - ear speculum - utilized to widen the
opening of the ear canal
 - floor lamp - necessary for viewing the
external and middle ear using a head mirror
 Head Mirror - used together with a floor
lamp and ear speculum to view external and
middle ear
 Otoscope - used in place of a head mirror
- does not require use of a floor lamp
because of its built - in light source
 Select correct size of speculum
 examine ear canal for inflammation, redness
of skin, secretions, impacted cerumen or ear
wax
 always disinfect speculum to avoid crosscontamination
OTOSCOPY
 Adequate examination of the external
auditory canal requires proper positioning of
the patient
 Patient’s head must be tilted towards the
opposite shoulder
 Since tilting the head is a position the
patients do not normally assume, you
should explain to them why you are doing
this
Otoscopy
 Examining an adult
 Examining a child/infant
 In adults, the tragus should be gently pulled
anteriorly and the pinna lifted in the postero
superior direction to straighten the ear canal
 In infants and young children, the pinna
should be pulled inferiorly because of the
downward curvature of the normal infantile
EAC
 In many individuals, the EAC is sufficiently
large that drawing the tragus anteriorly and
lifting the auricle upwards and posteriorly
opens the meatus sufficiently wide to give
us a good view of the EAC and tympanic
membrane (TM).
 If not, a nonreflective aural speculum can be
used to control the soft tissues of the lateral
EAC and thus facilitate visualization o the
medial EAC and TM.
 The largest speculum that will fit comfortably
gives the best exposure
 Use your non dominant hand to hold
speculum so the dominant hand can be left
free for instrumentation
INSERTING THE SPECULUM
 The hand holding the speculum should
gently rest against the patient’s head so that
inadvertent movement by the patient will
move the head and speculum together and
prevent accidental injury to the EAC or TM.
 Speculum should not be inserted past the
cartilaginous portion as this is the only part
which is mobile or stretchable
 Contact with the inner bony 1/3 of the canal
is painful and does nothing to enhance
visualization
Otoscope
Advantages:
- handheld, portable
- quick and easy to use
- with good magnification
- easily available and cheaper
Limitation:
- absence of binocular vision
Microscope
Advantages:
-allows binocular vision, maximum
illumination and magnification,
-leaves the dominant hand free for effective
and relatively easy instrumentation
Limitation:
-availability and cost
CERUMEN
 Typical pH of cerumen is 6.1
 Conveyed along the EAC by the normal
movements of the lower jaw while eating,
yawning, and talking
CERUMEN
 Consists of a combination of desquamated
epithelium, thick sebaceous gland
secretions, and thinner apocrine gland
secretions
 Water resistant, traps debris
 With both bacteriostatic and bactericidal
activity due to the presence of saturated
fatty acids, lysozymes and low pH
CERUMEN
METHODS IN CLEANING THE EAR
 Should always be done under direct
visualization using a cerumen spoon
 Using a handheld otoscope with magnifying
lens (operating otoscope)
 Aural Irrigation with warm water (not to be
performed among patients with perforated
TM’s, had otologic surgery, otitis externa,
and with acute episodes of vertigo)
CERUMEN
 Ceruminolytics –
also called “cerumen softeners”
– Hydrogen peroxide
– Mineral oil, baby oil
– Commercially prepared otic drops (Otosol,
Auralgan)
– Water
CERUMEN
After complete cerumen removal, evaluate the
size and shape of the EAC
If the diameter of the EAC is less than 4 mm., it is
considered stenotic
TYMPANIC MEMBRANE
 Eardrum-divides external from middle ear
 conical structure with the point of the cone,
umbo, directed medially
 outer -epidermal layer; middle- fibrous layer;
and an inner mucosal layer
 fibrous layer is absent above the lateral
process of malleus making it flaccid Sharpnell’s membrane
 Take note of the color of the tympanic
membrane
 Normally it is grayish with variable
transparency
 Covered by smooth squamous epithelium
 “cone of light” is seen at the anterior inferior
quadrant
 The tympanic membrane is mobile and to
perform its function, it should be able to
vibrate
 Restrictions in movement may be due to
effusion in the middle ear
 Ask patient to do Valsalva Maneuver to test
mobility or use a pneumatic otoscope
ANCILLARY PROCEDURES
IMAGING STUDIES
 Radiographic X-rays – done to visualize the
middle ear structures, should always
compare both sides, gives limited
information
– Schullers View – demonstrates mastoid air cells
– Stenvers View –demonstrates petrous ridge and
apex
COMPUTERIZED TOMOGRAPHY
 For temporal bone imaging
 With the ability to define specific bone
structures
 Axial and coronal cuts
MAGNETIC RESONANCE
IMAGING
 Best for detecting tumors, suspected
vascular lesions
 Less superior than CT in defining bony
structures
CLINICAL HEARING
TESTS
TUNING FORK TESTS
 Goal: to differentiate between conductive
and sensorineural hearing loss
 CONDUCTIVE Hearing Loss (CHL)- caused
by diseases of the external auditory canal or
middle ear
 SENSORINEURAL Hearing Loss(SNHL) –
caused by problems in the cochlea and
inner ear
 512 Hz TF - most commonly used
 Can use a TF that vibrates between 250 and
800 Hz
 Lower frequencies are avoided due to
interference from perception of low
frequency vibrations
- The TF should have a broad base
- The base of the TF should be pressed firmly
against the cranial bone inorder to transmit
the vibrations to the bone and overcome
dampening by the skin
WEBER TEST
 The TF is placed in the midline of the skull,
(vertex or forehead), vibration is transmitted
by bone conduction to cochlea
 When hearing is normal, vibrations are
perceived equally loud on both sides
(midway between the ears)
 Comparing the right and left ear
Weber Test (con’t)
 When hearing is abnormal, sound will
lateralize to one side
 SNHL – lateralizes to the better hearing ear
 CHL- sound lateralizes to the poorer hearing
ear because the vibrational energy is more
poorly transmitted from the cochlea through
the middle ear and would be harder for the
sounds to reach the cochlea
RINNE TEST
 In Rinne, we compare the levels of air and
bone conduction in the same ear
 Air conduction (AC) – tested by holding the
TF just outside the ear canal without
touching it
 Bone conduction (BC) – tested by pressing
the TF base firmly against the mastoid bone
Rinne Test (con’t)
 Patient is asked to compare loudness in the
1st position( AC) with the 2nd position (BC)
 Rinne Test Positive – AC > BC and lasts at
least 15 seconds longer
 Rinne Test Negative – AC< BC
BASIC AUDIOMETRY
 Audiometry – measurement of auditory
functions
 Goals: - detection
-lateralization
-quantification of a hearing disorder
 Human ear can perceive sound between 20 20, 000 Hz
 Velocity of sound ranges from 340m/s in air to
approximately 5000 m/s in solid media such as
bone
 Noise- most common acoustic stimulus
 Voice- most important sound source in humans
( approx. 100Hz- males, 200Hz- females)
Classification of Hearing Loss by
Severity (Quantification)
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Normal hearing - < 20 db
Mild hearing loss – 20-40 db
Moderate hearing loss – 40-60 db
Severe hearing loss - 60-90 db
Profound hearing loss – 90-and above
 Congenital deafness - refers to the absence
of hearing; failure of speech development
 Acquired deafness – loss of sense of
hearing; loss of speech comprehension;
have developed speech and language
development depending on age when this
occurred
BEHAVIORAL AUDIOMETRY
 Based on an active and usually voluntary
response from the test object
-Pure – tone audiometry
-Speech audiometry
-Response audiometry
OBJECTIVE AUDIOMETRY
 Based on objectively measured parameters
that represent an involuntary physiologic
response
- tympanometry
-otoacoustic emissions
-auditory evoked brain-stem potentials
(ABR, BAER)
PURE TONE AUDIOMETRY
 Calibrated AC and BC stimuli are presented
thru standard acoustic transducers (TDH39) or thru insert phones (ER-3A)
 Signals are steady or pulsed and has a
frequency range of 125 Hz to 8000Hz for AC
and 250 Hz – 4000 Hz for BC
 Signal levels are expressed in decibels (db)
 Makes use of an audiometer which is an
electronic instrument to test hearing
 Done in a sound treated room
 Audiogram –graphic representation of the
individual’s sensitivity for pure tones
 Red circle- refers to the right ear
 Blue or black X refers to the left ear
 Always test better ear first
 Assessing the threshold – (weakest level at
which a person will respond 50% of the time
) for each frequency
 Start with 1KHz, 2KHz,4KHz,8KHz, re-check
1KHz,500Hz, 250Hz, 125 Hz
Tones are presented to one ear at a time
Test for AC first using headphones or insert
phones
Prevent cross-hearing by masking
Test BC thresholds by using a vibrator pressed
against the mastoid bone ( set the skull into
vibration to transmit sound into the inner ear)
AUDIOGRAM
 Sensorineural hearing loss – no significant
threshold differences between AC and BC
thresholds
 Conductive hearing loss –if AC is higher
than BC by more than 10 db
 Mixed type of hearing loss – greater air
conduction compared with bone conduction
but both abnormal
SPEECH AUDIOMETRY
 Measures the recognition and
understanding of speech rather than the
threshold
 Speech material is available in standardized
form on compact discs and is presented at
designated levels using an audiometer
 Speech audiogram indicates the percentage
of syllables, words or sentences that the
subject has heard correctly
TYMPANOMETRY (Impedance
Audiometry)
 Sound vibrations are reflected in the
eardrum and sensitive electrical equipment
records objectively the mobility of the drum
 This test may show eustachian tube
problems, middle ear disease, or a
perforated drum
 Tympanogram – graphic results of an
immitance test
 Type A tympanogram has a prominent,
sharp peak between –100- 100 mmH20
 Type B tympanogram is flat or has a very
low, rounded peak. This indicates immobility
of the drum which may be due to fluid in the
middle ear
 Type C tympanogram has a peak in the
negative pressure region below –100
mmH20 consistent with impaired middle ear
ventilation
AUDITORY EVOKED POTENTIALS
(ABR,BAER)
 May be used in the diagnosis of neurologic
diseases
 Done to differentiate a cochlear froma
retrocochlear lesion
 Important for threshold testing in pediatric
audiology
OTOACOUSTIC EMISSIONS
 Clinically important in screening the function
of the cochlea in infants, newborns and
small children
 Provides a fast and simple way without
sedation or anesthesia thus facilitating early
detection of hearing problems
 Can also be used to investigate non-organic
hearing loss, assess cochlear functions in
high risk group and objectify audiometric
findings in adults
VESTIBULAR TESTS
 HISTORY
most important diagnostic tool
Quality
Temporal Course – speed of onset, duration
Associated symptoms
Exacerbating factors
Chronology
General Pattern
Auditory Symptoms – hearing loss, tinnitus
ear disease
Ocular problems
CNS - ataxia, dysequilibrium
Vestibular Examination
TWO PRINCIPAL COMPONENTS
Eye Movement Examination
Balance and Coordination examination
NYSTAGMUS
repetitive to and fro movement of the eyes
with a fast and a slow component brought
about by the imbalance of the tonic activity
of the vestibular system
 This involves carefully observing the eye
movements
 Has a slow component and a fast recovery
phase
NYSTAGMUS
 CAN BE:
– spontaneous
– Provoked
– induced
CALORIC TEST
 Each ear is irrigated for a fixed duration of 30-40
seconds
 Constant flow rate of water with a temperature of 7
degrees below body temperature (30 degrees)
and 7 degrees above (44 degrees)
 Supine position with the head tilted 30 degrees
forward
 Eyes open behind frenzel glasses,total darkness
Romberg’s Test
 Patient stands still with eyes closed
 Clasp hands together and pull apart inorder
to divert attention (Jendrasik Maneuver)
 20-30 seconds
 Positive Romberg’s - fall on either side
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