Audiology Final

What is the acoustic stapedial reflex?

An involuntary contraction of the stapedius muscle in response to loud sounds.

What is the main purpose of the acoustic reflex?

To help protect the inner ear from loud sounds.

What is the afferent (incoming) pathway of the acoustic reflex arc?

Outer ear → middle ear → cochlea → CN VIII → cochlear nucleus → superior olivary complex

What is the efferent (outgoing) pathway of the acoustic reflex arc?

CN VII (facial nerve) → stapedius muscle

Easy way to remember the acoustic reflex arc?

8 goes in, 7 comes out

What does ABR stand for?

Auditory Brainstem Response

What is ABR?

An electrophysiologic test that measures neural responses as sound travels through the auditory pathway.

What do ABR waveform peaks represent?

Neuroelectric events at auditory relay stations

In what time window does ABR occur?

0–15 milliseconds

What does Wave I represent?

Distal auditory nerve

What does Wave II represent?

Proximal auditory nerve + cochlear nucleus

What does Wave III represent?

Cochlear nucleus + superior olivary complex

What does Wave IV represent?

SOC + lateral lemniscus

What does Wave V represent?

Lateral lemniscus + inferior colliculus

Which ABR wave is most clinically important?

Wave V

What is absolute latency?

Time from stimulus onset to a wave peak

What is interpeak latency?

Time between two ABR waves

What does prolonged I–III latency suggest?

Lower brainstem lesion

What does prolonged III–V latency suggest?

Upper brainstem lesion

What does prolonged I–V latency suggest?

Whole brainstem lesion

What happens to latency as stimulus intensity decreases?

Latency gets longer

What happens to wave amplitude as intensity decreases

It gets smaller

Are ABR latencies longer in infants or adults?

Infants

In infants, which wave is usually larger: I or V?

Wave I

In adults, which wave is usually larger: I or V?

Wave V

What does a click stimulus test?

A broad range of frequencies

What does a tone burst test?

A specific frequency

What is the difference between TEOAE and DPOAE?

TEOAE uses a click, DPOAE uses two tones

What does TEOAE stand for?

Transient Evoked Otoacoustic Emissions

What does DPOAE stand for?

Distortion Product Otoacoustic Emissions

What formula is used for DPOAE?

2F1​−F2​

What cochlear region does DPOAE reflect?

Outer hair cell activity near the F2 region

What is a major limitation of OAEs?

They do not indicate severity of hearing loss

What is screening?

A rapid procedure to identify those with high probability of hearing loss

What is the two-stage newborn screening process?

OAE first → A-ABR second if fail/refer

Why are OAEs often done first?

Faster, easier, and good for initial screening

What is sensitivity?

Ability to correctly identify those with hearing loss

What is specificity?

Ability to correctly identify those without hearing loss

High sensitivity means what?

Low false negative rate

High specificity means low what?

False positives

What does BOA stand for?

Behavioral Observation Audiometry

What does VRA stand for?

Visual Reinforcement Audiometry

What does CPA stand for?

Conditioned Play Audiometry

What are reflexive behaviors?

Startle, eye blink, sucking change, limb movement

What are attentive behaviors?

Quieting, eye widening, localization, turning to sound

What is habituation?

Response decreases after repeated exposure to the same sound

What are the 1-3-6 goals?

1 month: screening

3 months: diagnosis

6 months: intervention

Which grades are routinely screened in NYS?

K–3, grade 7, and grade 11

Pure Tone

A simple sound consisting of a single frequency (single vibration)

Pure Tone Audiometry

A hearing test that determines the softest sound a person can hear at different frequencies

Audiometric Threshold

The softest level a person can hear a tone 50% of the time

dB HL

Decibels hearing level; unit used to measure hearing sensitivity

Audiometric Zero

0 dB HL; average normal hearing level

Normal Hearing Range

0–25 dB HL

Clinical/Diagnostic Audiometer

Device used to control frequency and intensity of sounds delivered to the patient

Portable Audiometer

Used for school screenings; typically air conduction only

Air Conduction Audiometry

Measures hearing through the normal outer, middle, and inner ear pathway

Transducer

Device that delivers sound (supra-aural or insert earphones)

Supra-aural Earphones

Headphones placed over the ears during testing

Insert Earphones

Earphones placed inside the ear canal; reduce collapse and external noise

Why can’t air conduction be better than bone conduction?

Because bone conduction bypasses the middle ear and directly stimulates the cochlea

What does air conduction testing measure?

Sensitivity of the entire auditory system

Can air conduction localize the site of damage?

No, bone conduction must also be tested

Bone Conduction Audiometry

Test that bypasses the middle ear to evaluate inner ear function

Bone Oscillator Placement

Mastoid or forehead

What happens during bone conduction regardless of placement?

The better cochlea always hears

Air Conduction Symbol (Right Ear)

O (circle)

Air Conduction Symbol (Left Ear)

X

Bone Conduction Symbol (Right Ear)

<

Bone Conduction Symbol (Left Ear)

>

Octave Test Frequencies

250, 500, 1000, 2000, 4000, 8000 Hz

Why is 1000 Hz tested first?

It is reliable and easy for patients to detect

Starting Intensity at 1000 Hz

30 dB HL

If no response at starting level

Increase intensity by 20 dB

Down 10, Up 5 Rule

Decrease 10 dB after response; increase 5 dB after no response

Threshold Definition

Lowest level heard 50% of the time

When should inter octave frequencies be tested?

When there is greater than a 20 dB difference between octave frequencies

Why are 250 and 500 Hz important?

They fall in the speech banana and represent vowel sounds

Response Modes

Hand raise, response button, play audiometry, visual reinforcement, behavioral observation

Purpose of patient instructions

To ensure accurate and reliable responses

What does bone conduction help differentiate?

Conductive vs. sensorineural hearing loss

Air Conduction Determines

Degree of hearing loss

Bone Conduction Determines

Type of hearing loss

Conductive Hearing Loss

AC =impaired, BC = normal, air bone gap

Sensorineural Hearing Loss

AC = impaired , BC = impaired, NO air bone gap

Mixed Hearing Loss

AC = impaired, BC = impaired, air bone gap

Normal

-10 to 15 dBhl

Mild Hearing Loss

26 to 40 dBhl

Moderate Hearing Loss

41 to 55 dBhl

Moderately severe Hearing Loss

56 to 70 dBhl

Severe Hearing Loss

71 to 90 dBhl

Profound Hearing Loss

< 90 dBhl

dB spl

Sound pressure level; 0 dBspl = 20 micropascals

Air bone gap

 difference between AC and BC greater than 15 decibels; Comparing AC to BC in the same ear 

Audiologist

a person in the field of research and clinical practice devoted to the study of hearing disorders, assessment of hearing, hearing conservation, and aural rehabilitation 

Scope of Practice for SLP

Collaboration, counseling, prevention and wellness, screening, assessment, treatment, modalities technology and instrumentation, and population and systems

Scope of Practice for the Audiologist

Diagnostics of Hearing and Balance, Treatment of Hearing and Balance, Early Hearing Detection and Intervention, Educational Audiology, Hearing Conservation and Preservation, Telehealth, Counseling

ASHA certification standards for AuD

Standard I: Academic Qualifications, Standard II: Knowledge and Skills, Standard III: Verification of Knowledge and Skills, Standard IV: Examination (Praxis exam in audiology), Standard V: Maintenance of Certification

Scope of practice

an outline of the parameters of each of the professions 

Sound

A physical phenomenon which describes a movement or vibration of an elastic medium without permanent displacement of the particles