Principles of Acoustic Imittance

Question 1

Specificity

Answer 1

The probability of a test being negative when a disease is not present

Question 2

Sensitivity

Answer 2

The probability of a test being positive when a disease is present

Question 3

Acoustic Admittance

Answer 3

The ease with which energy flows through an acoustic system; the reciprocal of acoustic impedance.

Question 4

Acoustic Impedance

Answer 4

Opposition within a system to the flow of acoustic energy; the reciprocal of acoustic admittance.

Question 5

Resonance

Answer 5

The acoustic phenomena where a sound wave is amplified when it matches the natural vibrating frequency of a system

Question 6

Force

Answer 6

An action that is capable of moving a body at rest or changing the motion of a body in motion.

Question 7

Pressure

Answer 7

Force per unit of area

Question 8

Volume Velocity

Answer 8

Volume of a medium (e.g., air) that moves past an imaginary plane per unit time

Question 9

Acoustic Mass

Answer 9

Ratio of sound pressure to the resulting change in volume velocity. An acoustic mass element is a volume of air that moves as a unit in response to sound, such as the air in an open tube.

Question 10

Acoustic Stiffness

Answer 10

Ratio of change in sound pressure to the resulting change in volume displacement. An acoustic stiffness element is a volume of air that is alternately compressed and expanded by sound, such as air in a rigid enclosure.

Question 11

Acoustic Reactance

Answer 11

The impedance within a system due to mass and compliance elements; the reciprocal of acoustic susceptance.

Question 12

Acoustic Susceptance

Answer 12

The admittance within a system due to mass and compliance elements; the reciprocal of acoustic reactance.

Question 13

Acoustic Resistance

Answer 13

The impedance within a system due to friction; the reciprocal of acoustic conductance

Question 14

Acoustic Conductance

Answer 14

The admittance within a system due to friction; the reciprocal of acoustic resistance

Question 15

Why do we measure imittance in units of admittance

Answer 15

Ear canal volume between the probe tip and the tympanic membrane does not
affect the shape of admittance tympanograms and simply shifts the baseline; the shape of admittance tympanograms is more susceptible to changes in middle ear condition compared with impedance tympanograms

Question 16

Why don’t we measure imittance in units of impedance

Answer 16

The shape of impedance tympanograms is greatly affected by the ear canal volume; the shape of admittance tympanograms is more susceptible to changes in middle ear condition compared with impedance tympanograms