Immittance

Question 0

Admittance

Answer 0

Ease with which energy flows through a system

Question 1

Immittance

Answer 1

How readily a system can be set into vibration.

-incorp recipie ok concepts of admittance and impedance

Question 2

Impedance

Answer 2

Extent to which the system resists the flow of energy

Question 3

3 measurements collected in immittance

Answer 3

1. Static acoustic compliance (tympanonmetey)
2. Tympanometry
3. Acoustic reflex

Question 4

Tympanometry

Answer 4

ME admittance measure

-goal is to define the point and magnitude if greatest compliance of TM

Question 5

Tympanogram

Answer 5

Admittance - y axis

Air pressure in ear canal - x axis

Question 6

Admittance measures

Answer 6

1. static acoustic admittance
2. Equivalent ear-canal volume
3. Tympanic peak pressure
4. Shape

Question 7

Static acoustic admittance

Answer 7

Peak y
Measures mobility of TM
Peak max compliance - where pressure on both sides is equal
Total A = y(outer ear) + y(middle ear)
Redu SAA - fluid filled mE or ossicles not vib
Inc SAA- dis artic of ossicles or abnormal elasticity of TM

Question 8

ECV

Answer 8

Vol of air in front of probe (medial) and lateral to tM

Abnormal ECV - proliferation in TM; tube in TM (little to no compliance); small (wax impact ion)

Question 9

Tympanometric Peak Pressure (TPP)

Answer 9

Measure (indirect air pressure in ME

Question 10

Shape of tympanogram

Answer 10

Type A - normal
Type As - shallow peak 
Type Ad- deep peak 
Type B - flat 
Type c - negative peak

Question 11

Acoustic reflex testing

Answer 11

Results from contraction of ME muscles (stapedius) in response to intense sounds
-stiffens ME - decreases SAA

Question 12

Two pathways for acoustic reflex

Answer 12

1. Ipsilateral : signal and decrease in compliance - same ear
2. Contra lateral : dec in TM compliance in ear opposite to ear that receives signal

Question 13

Acoustic reflex threshold (ART)

Answer 13

Lowest intensity level at which there is a measure able admittance change in ME system as a function of intense sound stimulation

Question 14

Four outcomes of ART

Answer 14

1. Present at norm SL (~85dBSL)
2. Absent at limit of system (~110 dBHL)
3. Present but at low SL (100 dBSL)

Question 15

Otoacoustic emissions (OAE)

Answer 15

Generated from normal cochlea in the outer hair cells.

Function: sharpen or amplify the cochlea traveling wave.

Question 16

Two classes of OAEs

Answer 16

1. Spontaneous: occur w/o acoustic stimulation. Occurs in 50%
2. Evoked: occur with stimulation

Question 17

Evoked OAEs - two types

Answer 17

1. Transient evoked too acoustic emissions (TOEAEs). Obtained by presenting a brief stimulus - broadband
2. Distortion product emissions (DPOAEs). Result from interaction of two simultaneous pure tones

Question 18

Evoked oAEs - when present and absent?

Answer 18

Present - when hearing t/holds are normal

-absent in frequency regions where there is cochlear hearing loss of 40-50dB HL or more

Question 19

Auditory Evoked Potentials (AEP) also ABR (auditory brain stem response)

Answer 19

Measurement if time that elapses from acoustic stimulus presented and time it takes for brain to generate electrical activity in response to stimulus
Short middle and long latencies