Audiology chapter 6 exam 2

Diagnostic Testing

Comprehensive hearing evaluation

Types of comprehensive hearing evaluation

• air conduction pure tone testing 

• bone conduction pure tone testing 

• Speech recognition threshold

• speech recognition score 

What information can further audiological testing provide?

• Differentiation between sensory (cochlear) and neural (retrocochlear) hearing loss

• Site of lesion using modern audiological tests

Why is audiologist testing still important despite modern imaging

Audiologoical testing can determine the site of lesion and provide a full auditory diagnosis complementing imagining techniques

What are phsyiological test used fro in audiology ?

-validate or differentiate diagnosis 

asses difficult to test clients 

detect malingering 

What is the main characteristic of physiological test

they do not require behavioral responses from the client

What are the two types of physcological test

Electroacoustical 

Electrophysiological 

What test are included uner electroacoustic measures 

Typanometry (Tymp)

Otoacoustic Emission (OAEs)

Acoustic Reflex Testing (ART)

What equipment is used to measure electroacoustic functions?

Acoustic Immittance Meters

What does tympanometry measure ?

Middle ear pressure via TM (tympanic membrane) mobility in response to air pressure changes 

What is the static acoustic compliance (SC)?

Measure of TM mobility as specific air pressures; part of tympanometry

What does C1 represent in tympanometry

TM mobility when loaded with +200 daPa (immobile TM)

What does C2 represent in tympanometry?

Maximum TM mobility (negative pressure; best compliance)

What does Cx represent ?

static compliance of the middle ear

How is Cx calculated

Cx= C2- C1

What are the normal static compliance ranges for children 3-10 years ?

.25- 1.05ml

What are the compliance ranges for adults 18 years and over

0.30- 1.70ml

What causes below normal static compliance ?

• Increases stiffness

• increased mass

• Increases resistance 

What causes above normal static compliance

• decreased stiffness 

• decreases mass 

What are alternate names for tympanometry

• immittance testing 

• impedance testing 

• middle ear evaluation

What parameters foes tympanometry evaluate

• ear canal volume 

• middle ear peak pressure

• TM mobility 

• Impedance 

• static compliance 

• Admittance 

• ossicular structure 

When does the TM vibrate most effciently

when pressure is equal on both sides of the TM

What determines resistance, mass, and stiffness in acoustic immittance

• Resistance: ligaments supporting ossicles

• Mass: ossicles and TM

• Stiffness: Fluid pressure in cochlea at base of stapes 

What is reactance ?

A combination of mass and stiffness in the middle ear system 

How do reactance and frequency interact ?

As frequency increases

How are mass and stiffness related to compliance ?:

As stiffness rises compliance falls

Compliance is the inverse of stiffness 

Mass and stiffness are frequency dependent 

What componets make up a tympanometry probe

• Minature loudspeaker (226 Hz tone)

• tiny microphone (measures sound in EAC)

• Air pump (changes air pressure) 

What frequency tone is used in tympanometry for adults

226 Hz