exam 2

audiology

Ototoxicity

•Damage to the organ of hearing resulting
from:
•Noxious substances
•Therapeutic agents
•Chemotherapy drugs
•Aminoglycosides
•Loop diuretics
•Salicylates (aspirin)
•Anti-malaria drugs (quinine)
•Many can damage other organ systems
besides the ear

Timeline of embryology

genetic disorders

key features

usher syndrome

• One of most common syndromic hearing losses
• Affects retinas in both eyes (retinitis pigmentosa) causes night blindness and vision
loss
• Autosomal Recessive Inheritance

Waardenburg syndrome

• Autosomal Dominant Inheritance, 1-3% of all congenital hearing losses
• Disorder of pigmentation of various parts of the body including:
• Eyes
• Hair
• Skin
• Stria vascularis in the cochlea
• 4 Classifications: Pigmentation may vary, often blue eyes and white
forelock
• W1 60% will have SNHL, dystopia canthourm (eyes appear wide-set)
• W2 90% will have SNHL
• W3: SNHL, dystopia canthorum and musculoskeletal abnormalities of the upper
limbs

Pendred syndrome

• Most common cause of autosomal recessive syndromic HL
• Associated with broad range of hearing loss
• Often includes Enlarged Vestibular Aqueduct (EVA)
• Progressive hearing loss – at times sudden
• Progressive vestibular dysfunction possible (65%)
• May include Mondini malformation
• Not enough turns in the cochlea
• Goiter is a hallmark
• Thyroid dysfunction Mondini’s

branchio-oto-renal

• Autosomal dominant inheritance
• Disruption of the development of tissues in the neck and malformations
of the ears and kidneys
• Branchio – Refers to the second branchial arch
• May result in cleft cysts or pits near the collar bone
• Oto – Hearing loss can be any of the three types
• May have pre-auricular pits or tags
• Renal – Kidney structure abnormalities
• Can result in end-stage renal disease in later life

charge syndrome

C – Coloboma (gap or hole in the iris/eyelid)
H – Heart defects (varies)
A - Choanal Atresia (narrowing of the nasal passages)
R - Restriction in growth and development (varies)
G - Genital Abnormalities (varies)
E - Ear Abnormalities (middle and inner ear problems
including hearing and balance)
• Autosomal dominant inheritance
• Presentation varies widely from patient to patient

alport syndrome

• 80% of cases are X-Linked
• Causes progressive kidney failure leading to end-stage renal
disease
• May need dialysis and kidney transplant
• Progressive SNHL hearing loss which can progress to
profound
• Usually identified in late childhood (school age)
• May require cochlear implantation

jervell and lange-nielsen

• Autosomal recessive inheritance
• Congenital SNHL
• Arrhythmia
• Prolongation of the QTc interval resulting
in fainting/and or sudden death

stickler syndrome

• Can be both dominant or
recessive
• Includes differences in:
• Eyes (severe myopia)
• Musculoskeletal (joint laxity)
• Orofacial structures
• Ears and hearing
• 5 different subsets depending
on genes encoding different
collagen types

teacher-collins syndrome

• Autosomal Dominant
inheritance
• Effects development of the
bones and tissues of the face –
midface
• Often affects jaw which can
impact airway, feeding, and
speech
• Roughly half have hearing loss
• Generally conductive hearing
loss
• Due to abnormalities of the
outer and middle ear

otitis externa

outer ear --- viral, bacterial, or fungal infection of the ear canal

otitis media

middle ear

Vea

Volume in ear canal

Ytm

admittance/compliance --- Y axis

TPP

tympanic peak pressure --- x axis

TW

tympanic width
-the pressure range of a tympanogram at a defined point
-calculated at half of Ytm value
-Reported as the absolute value of the range between the two
frequencies

CAPD

central auditory processing disorder

-We use a battery of listening tests to identify patterns of listening difficulty and develop skill profiles

- If someone has a diagnosis involving another neurologic process, we do not assess CAPD

- It is much more likely that the other diagnosis is responsible for any processing deficits

ABR

auditory brainstem response test

Objective measurement of the auditory system including the nerves up to the
brainstem

Tone burst

• Tone bursts are not technically tones

• They are filtered noise that mimics the effects of a tone

• Work to identify the 5th wave of the auditory pathway

• Trace the 5th wave down until we find the quietest level we can see a response

Clicks

Used for Neural Assessment

• Broadband noises that includes many many frequencies

• Goal is to stimulate a large portion of the organ of hearing in order to make a very large response.

• We work to identify the 6 major waves created by the auditory pathway

wave 1

cochlea

wave 2

8th CN

wave 3

cochlear nucleus

wave 4

superior olivary complex

wave 5******

lateral lemniscus****

wave 6

inferior colliculus

Tone burst stimuli

loud tone bursts (look at wave 5)

ART

Acoustic Reflex Threshold (ART)

• Tympanogram performed to find TPP

• Ear is pressurized to TPP value (best movement of eardrum)

• Testing is performed with several different tones or noise (500 Hz)

• Sound is presented at a loud level and the contraction is measured

• Identify the softest sound the reflex is elicited (.02 or greater)

Suspected Otitis Media with Effusion

Type B

Resolving Otitis Media with Effusion

Type As

Negative Middle Ear Pressure

Type C (Eustachian tube malfunction)

Patent Pressure Equalization Tube

Perforation in the eardrum

Disarticulation of the Ossicles

TEOAEs Transient Evoked Otoacoustic Emissions

Noise stimulus
many sounds can be measured all at once
They will always show:

• The Reproducibility

• The level of loudness of the Emission

• The amount of noise

• The signal to noise ratio

TEOAEs Test Frequencies and Norms

TEOAEs can test from: ~1000 to 4000 Hz
• SNR must be greater than greater than 6 dB
• 99% of ears will have TEOAEs if hearing is 20 dB
HL or better
• TEOAEs will be absent if hearing loss is greater
than 30 to 35 dB HL
• TEOAEs are always absent when hearing
thresholds are greater than 40 dB HL
• TEOAEs may or may not be present when
thresholds are 25 to 35 dB HL

TEOAEs can test from

1000 to 4000 Hz

TEOAE Threshold level

TEOAE Present? Yes

TEOAE Threshold level 25 to 35 dB HL

TEOAE Present? Maybe

TEOAE Threshold Level >40 dB HL

TEOAE Present? Never

DPOAEs Distortion Product Otoacoustic Emissions

Tonal stimulus
one frequency assessed at a time
All machines will provide some
thing similar

• They will always show:

• The Reproducibility

• The level of loudness of the emission

• The amount of noise

• The signal to noise ratio

DPOAEs can test from

1000 to 6000 Hz or higher in certain circumstances

Test Frequencies and Norms DOPAEs

DPOAEs can test from: ~1000 to 6000 Hz
or higher in certain circumstances

• SNR must be greater than greater than 6
dB

• DPOAEs will be present if hearing is 25
dB HL or better

• DPOAEs are generally absent when
hearing thresholds are greater than 40
dB HL

• DPOAEs may or may be present but low
amplitude (weak) between 40 to 60 dB
HL

DPOAEs Threshold level

DPOAE present? yes

DPOAE Threshold level >40 dB HL

DPOAE Present? Generally no

DPOAE Threshold level 40 to 60 dB HL

DPOAE present? Possible

CAPD Battery of tests

• Meant to overwork the systems in
order to evaluate breakdown

• Age-matched norms

• Evaluate patterns in test findings:
develop performance profiles

• Define specific nature of the problem
• Is it just binaural processing, a mix?
• Concern for other disorders

Types of Behavioral Tests

-Temporal Processes – Pattern perception, gap detection

• Dichotic Listening (Speech Tests) – Different words or sentences presented to each ear, but patient listens only in one ear

• Monaural Low-Redundancy – Filtered speech, compressed speech

• Lateralization, localization, or binaural functions

• Auditory Discrimination Tests – Frequency, intensity, and duration of speech stimuli

Temporal Processes

Pattern perception, gap detection

Dichotic Listening (Speech Tests)

Different words or sentences
presented to each ear, but patient listens only in one ear

Monaural Low-Redundancy

Filtered speech, compressed
speech

Auditory Discrimination Tests

Frequency, intensity, and
duration of speech stimuli

Three major CAPD Profiles

Decoding deficits
Integration deficits
Prosodic deficits

Decoding deficits (true capd)

-System is unable to extract pitch,
loudness and timing cues

-Considered truest of all CAPDs because
it’s all auditory-based deficit

-Discrimination based problem,

-Located in left hemisphere and/or high
brainstem

Integration deficits

Deficit in the communication between the
right and left hemispheres (cortical)

Unable to combine information and synthesize
meaning (i.e. can’t put it all together)

Hard to process information quickly

System becomes easily overwhelmed when
lots of information is given

Prosodic deficits

Unable to process the rise and fall in
pitch and loudness (syllabic
emphasis/intonation)

Right hemisphere problem (aka Right
Hemisphere APD)

Difficulty with analysis and synthesis of
prosodic features related to
communication

Treatment for APD

bottom-up (stimulus driven)
tom-down (strategy driven)

Bottom-Up (stimulus driven)

Auditory training
Skills remediation
Environmental modifications including assistive
technologies

Top-down (strategy driven)

• Language, cognitive, metacognitive strategies
• Educational interventions
• Workplace, recreational, and home accommodations

Bottom-up examples

• You will listen to two sounds
• Tell me which sound is higher
pitch

• You will listen to two words, one
in each ear
• Tell me what word you heard in
the left ear only.

top-down examples

• You are going to listen to a
sentence. There will be one word
missing.
• I want you to use the context from
the rest of the sentence to figure out
the missing word.


“Billy is going to the movie that
_____ at 4:30 this afternoon.”

Hearing aid fitting workflow

assessment, treatment planning, selection, development, verification, orientation, validation

assessment

Identify hearing loss and determine
candidacy for hearing aids

treatment planning

Review results and options with
patient

selection

Matching hearing aid features with patient’s
needs

development

Formal gold standard prescriptive
methods to program hearing aids

verification

Ensure that hearing aids are functioning
properly and meeting expected prescriptive targets

Orientation

Instruct patient on hearing aid use and care,
as well as explain realistic expectations

validation

Measure patient’s subjective experience,
AND some objective measurements of benefit

Candidacy for hearing aids

Assessment of hearing loss

Resolution/consideration of medical issues related to ear

Consideration of patient interest

Audiometric Candidacy:
• Minimum: Mild hearing loss in the 500 to 4000 Hz region
• Severity: If hearing loss is too great, may need cochlear implant
• Word Recognition Scores: Poor word recognition may impact benefit
• Speech in Noise Testing: Results may indicate the need for advanced
technologies to help in noise
• Loudness Discomfort Level (LDL)/Uncomfortable Level (UCL):
Patient may not be able to tolerate loud sounds

Digital Features

multiple channels, multiple programs, compression (automatic gain control (AGC)): two functions, Wide Dynamic Range Compression, directional microphones, feedback reduction, linked hearing aids, data logging

multiple channels

Able to adjust hearing aid output in discrete frequency regions

multiple programs

Automatic or user-controlled programs based on patient’s needs in various settings

Compression (Automatic Gain Control (AGC)): Two functions

Limit how loud sounds get and minimize distortion

Wide Dynamic Range Compression (WDRC)

Preserve the experience of loudness
• When all sounds are amplified, how can you tell if what you hear is quiet, medium, or loud??

directional microphones

One forward facing and one rear facing
microphone
• Allows the hearing aid to determine the location of speech versus noise
• Processing allows for digital noise reduction
• Digital Noise Reduction: Reduces background noise based on it’s
frequency range and location

feedback reduction

Phase cancellation of feedback sounds

linked hearing aids

Sounds from one hearing aid can be transmitted
wirelessly to the opposite ear

data logging

• How long hearing aids worn
• User adjustments to volume and programs
• Assessment of patient’s environments throughout the day

validation - are the hearing aids helping?

Aided testing:
• In a soundfield with speech stimuli
• The Ling 6 Sounds for thresholds
• Word Recognition in Quiet
• Speech in noise testing
• DO NOT Use pure tone stimuli or narrowband
• Hearing aid processor may view as
feedback or noise
• The hearing aid would make them quieter

validation-continued

Self-report tools
• Standardized forms allow to track patient
perceptions and progress
• Client Oriented Scale of Improvement (COSI)
• Pre-test to define goals and manage expectations
• Filled out over time to determine if goals are met or
adjustments needed.

• Abbreviated Profile of Hearing Aid Benefit
(APHAB)
• Evaluate patient’s perception of benefit in different listening environments
• Can do pre and post test
• Lots of normative values

verification

• Just because the programming software
says it’s programmed perfectly DOES NOT
mean it is set correctly in the real world!

• Ear acoustics can affect the output of the
hearing aid
• Could overamplify some sounds
• Could reduce amplitude of other sounds


• Two methods to verify:
• Test box
• Real ear measurement

Test Box Verification

• Hearing aids placed in
sound treated chamber

• Connected to ear
simulator (coupler)

• Speech sounds are
played into the hearing
aids

• Can ESTIMATE how
sounds are likely to
behave based on
programming

Real ear verification

• BEST way to measure hearing aid output

• Microphone placed in ear canal

• Hearing aid placed on ear and turned on

• Speech sounds are played from a speaker

• Can objectively measure EXACTLY how sounds are likely to behave based on programming

BAI - sound processor attachment

percutaneous, transcutaneous

percutaneous

an abutment is attached to implant and
comes through the skin (Direct Drive)
◦Provides best sound quality
◦More prone to infection

transcutaneous

a magnet is attached to the implant and
is completely under the skin (Skin Drive)
◦Poorer sound quality (less access to high pitches)
◦Less likely for infection
◦Prone to fall/be knocked off of the head

hearing aids

Hearing Aids/BAI/MEI
Drive the natural hearing
system to create neural
responses in the cochlea

Cochlear implants

Bypass the natural
hearing system to
stimulate the auditory
nerve directly

Microtia

external ear is small and not formed properly

Atresia

born with no ear canal

pre-auricular tag

ear tag

pre-auricular sinus

ear pit

tympanometry

dynamic measure of the acoustic imminence in the external ear canal as a function of ear canal air pressure change
– Provides information regarding mobility
(compliance) of the tympanic membrane
– Guides us in determining the status of the ME
– Cross check assessment that aids in differential
diagnosis

Immittance

assessment of middle ear function

Impedance

the opposition to the flow of energy
-blockage, resistance

admittance

measure of how much energy passes through a system

high admittance

greater flow of energy through the system