Wk 3 - Frequency & Immitance

Question 1

Stiffness effects will _____ as frequency increases

Answer 1

decrease

Question 2

_____ effects will increase as frequency increases

Answer 2

Mass

Question 3

Since the factors we want to add have relationships 90 and 180 degrees from each other, what can we use to add them?

Answer 3

Vectors - they have magnitude and direction. So to calculate the sum, we use pythagorean theorem

Question 4

_______ is the linear sum of stiffness and mass

Answer 4

Reactance

Question 5

The resonant frequency is the frequency at which mass and stiffness cancel each other out, leaving only ______

Answer 5

resistance

Question 6

The stiffness of the middle ear is created by what three things?

Answer 6

• the air cushion of the middle ear space
• the membranes
• the ossicular attachments

Question 7

The middle ear system’s mass is determined by what two things?

Answer 7

The TM and ossicles

Question 8

The resistance of the middle ear is determined by what two things?

Answer 8

The ME airflow and cochlear fluid (as stapes articulates with the oval window)

Question 9

What are the electrical counterparts of stiffness, mass, and resistance?

Answer 9

Stiffness = capacitance
Mass = inductance
Resistance = resistance

All 3 are measured in ohms

Question 10

_____ inhibits the flow of energy and ____ allows it

Answer 10

Impedance inhibits (ohms)
Admittance allows (mmho)

Question 11

When an ME system measures impedance, the resulting waveform shows:

Answer 11

Impedance (Z)

Question 12

When an ME system measures admittance, the resulting waveform shows:

Answer 12

Actually, 2 waveforms:
Conductance (G) and
Susceptance (B)