chapter 1

Question 1

Audiology

Answer 1

the healthcare profession devoted to
The prevention, identification, and evaluation of hearing disorders (including balance disorders)

Question 2

Educational preparation

Answer 2

Doctoral entry-level degrees
Clinical PhD/ScD
Professional doctorate AuD
PhD
Professional certification
American Speech–Language Hearing Association (ASHA): the national organization that certifies audiologists and speech–language pathologists in the United States
Certificate of Clinical Competence (CCC)
American Academy of Audiology (AAA)

Question 3

Professional licensure

Answer 3

State licensing board
Most states model their regulatory rules in audiology after the ASHA standards for the certificate of clinical competence
Continuing Education Units, around 30 per 3 years
Required by most states to maintain licensure
Often, separate licenses for audiology and hearing aids
Less schooling required to become a hearing aid dispenser (i.e., associate’s degree)

Question 4

Evolution of the profession

Answer 4

Relatively new profession
Began in 1940s
Roots took hold in the United States following WWII
Clinics set up to rehabilitate veterans with hearing loss
Non-VA diagnostic clinics (both independent and within physician offices) set up later
Hearing aids dispensed by dispensers (not audiologists)

Question 5

Scope of practice

Answer 5

Comprehensive audiometric evaluation (CAE)
Includes evaluation of middle ear function using immittance measures (tympanometry, acoustic reflex)
Auditory brainstem response (ABR) evaluation
Intraoperative monitoring of CN VII and CN VIII
Otoacoustic emission (OAE) evaluation of outer hair cell function
Electronystagmography (ENG) evaluation and vestibular rehabilitation
Cochlear implant programming/mapping of speech processor
Prescriptive fittings of hearing aid and assistive listening devices

Question 6

ACOUSTICS

Answer 6

1) the properties or qualities of a room or building that determine how sound is transmitted in it.
2) the branch of physics concerned with the properties of sound.

Question 7

PSYCHOACOUSTICS

Answer 7

Interdisciplinary science of the perception of sound.
2) Audiology

Question 8

Prevalence

Answer 8

Prevalence refers to proportion of persons who have a condition at or during a particular time period,

Question 9

Incidence

Answer 9

Incidence refers to the proportion or rate of persons who develop a condition during a particular time period.

Question 10

Sound

Answer 10

Sound: the movement of a disturbance (vibration) through an elastic medium (liquid/solid/gas) without permanent displacement of the particles
◦We are generally concerned with AIR

Question 11

Hearing

Answer 11

Hearing: the perception of sound

Question 12

Mass

Answer 12

Mass: quantity of matter present
•Not identical to weight (because weight is affected by gravitational force)
•For our purposes, mass ~ weight

Question 13

Force

Answer 13

Force: a push or a pull on an object; a vector

Question 14

Inertia

Answer 14

Inertia: tendency to resist any change in motion (Newton’s First Law)
•Outside force must be applied to change this tendency
•The greater an object’s mass, the greater its inertia

Question 15

Elasticity

Answer 15

–Elasticity: tendency to resist deformity of an object and to return to its rest position

Question 16

Nature of sound

Answer 16

Initial impact starts movement (displacement) away from rest

2)Elasticity in the fork allows displacement, but also generates a restoring force that stops the movement

3)Restoring forces push the fork back to rest position

4)Inertia carries the tines past rest position (overshoot)

5)Restoring force builds up in the other direction

6)Fork returns to rest position again (one full cycle)

7)Overshoots . . . builds up restoring force . . . the pattern repeats

In an elastic medium such as air, the molecules next to the sound source move first. Then, they pass the movement to adjacent molecules. This motion is propagated, or transferred, through the air to the ear.

Question 17

Compression

Answer 17

Compression: occurs when air particles are pushed together, resulting in an increase of air pressure; aka condensation

Question 18

Rarefaction

Answer 18

Rarefaction: occurs when air particles are separated, resulting in a decrease of air pressure

Question 19

Sound in air: longitudinal

Answer 19

Sound in air: longitudinal (pressure) wave
◦Particles vibrate alternately in the same direction of propagation (away from/toward the source) so that propagation is parallel to energy source
◦Particles approach and recede from each other to create pressure variations

Question 20

Simple harmonic sound

Answer 20

Simple harmonic motion: the symmetrical to-and-fro motion of a body over a rest position
◦When the amplitudes of the vibrating body are plotted as a function of time, the resulting pattern is a sine wave
◦Pure tones, sounds with definite tonal quality, are produced by simple harmonic motion

Question 21

Frequency

Answer 21

Frequency: a measurable characteristic of acoustic signals that is described by the number of complete cycles that a periodically vibrating source passes through in a 1-second time period
◦Measured in units called Hertz (Hz)
In a pure tone, only one frequency is described (e.g., 1000 Hz)
◦A sinusoid—forms a sine wave when graphed
◦Periodic in nature—repeats at regular intervals over time

Question 22

Octave

Answer 22

Octave: twice the frequency of a given frequency
◦Octaves assessed via audiometer:
◦250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz, 8000 Hz

Question 23

Pitch

Answer 23

◦Pitch: related to the listener’s perceptual response mainly to frequency (and, to a degree, intensity)
◦Frequency and pitch are related
◦Higher perceived pitch results (mostly) from higher frequency
◦However, this relationship is non-linear, especially at frequencies > 1000 Hz

Question 24

Amplitude

Answer 24

Amplitude: a derived unit of measurement that describes the distance that the sound-producing body moves during vibration
◦The greater the distance from the point of rest, the greater the amplitude
◦In general, the greater the amplitude, the louder the sound
◦Decreases over time as energy is lost to damping (friction and other outside forces)

Question 25

Intensity

Answer 25

Intensity: a derived unit of measurement that describes the amount of acoustic energy that passes through a unit of area in a given time span
◦Measured in units of power or pressure directly

Intensity versus loudness
◦Intensity: amplitude (magnitude) of the sound

Question 26

Pascal

Answer 26

Pascal: unit of pressure describing the force per unit area; measured in N/m2 or dyne/cm2

◦Bel: unit of power
◦Decibel: one-tenth of a Bel (dB)
◦Logarithmic
◦Ratio of the measured pressure to a reference pressure (I/Ir)

Question 27

Loudness

Answer 27

◦Loudness: the perception of intensity

Question 28

Periodic vibration

Answer 28

Periodic vibration: vibration that repeats itself regularly over time
◦Recurs in the same way
◦Takes the same amount of time to complete each successive to-and-fro movement of one cycle of vibration

Question 29

Aperiodic Vibration

Answer 29

Aperiodic vibration: vibration that is not repeatable over time
◦Generally classified as noise

Question 30

Velocity

Answer 30

◦Velocity: magnitude of distance traveled per unit of time
◦Denoted by c (celeritas; Latin for speed or swiftness)
◦As sounds are physical phenomena, they obey physical laws (such as those governing velocity of objects traveling through a medium….like air)
◦How fast the sound wave moves depends on the density and elastic properties of the medium though which it is moving
◦In dry air at 20 °C (68 °F), the speed of sound is 344 m/s (1235 km/h, or 758 mph, or 1130 ft/s)

Question 31

Inverse square law

Answer 31

Inverse Square Law: intensity varies inversely as the square of the distance from the sound source

Another look at the inverse square law; this is why classroom acoustics must be managed for optimal learning.

Question 32

Free vibration

Answer 32

◦Free vibration: vibration of a mass independent of the application of any external force

Question 33

Natural (resonant) vibration

Answer 33

Natural (resonant) vibration: frequency at which a mass vibrates with the least amount of external force
◦Vibration of an object greatest when vibratory frequency coincides with its resonant frequency

Question 34

Force vibration

Answer 34

Forced vibration: application of additional force to sustain the vibration; vibration of a mass controlled and maintained by the application of an external impetus
Friction opposes vibration
◦Gradual decay in vibratory amplitude over time

Question 35

the speed of sound

Answer 35

In dry air at 20°C (68°F), the speed of sound is 344 m/s (1235 km/h, or 758 mph, or 1130 ft/s)

Question 36

Ranges

Answer 36

20 Hz - 20,000 Hz ( range of human hearing)
250 Hz - 8000 Hz (ranges of testing hearing)
0 Db - 140 dB (how we measure intensity) we can hear beyond this but it will damage our hearing