Hearing Science Test 1

Front 1

is related to the distance that the sound-producing body (the vibrator) moves during vibration. The greater the distance from the point of rest, the greater the _______.

Back 1

Amplitude

Front 2

the excursion distance at any point in time

Back 2

instantaneous amplitude

Front 3

greatest point of displacement

Back 3

peak amplitude

Front 4

statistical average of all amplitudes at all times

Back 4

RMS (root-mean-square) amplitude

Front 5

vibration that is not repeatable over time. Sounds produced by this are generally classified as noise

Back 5

aperiodic vibration

Front 6

an instrument for measuring hearing thresholds. Hearing measurements are typically obtained for both pure tone and speech signals. The stimuli produced are presented to the listener through a pair of earphones, a bone conduction vibrator, or loudspeaker. The level of the stimulus is controlled by the examiner until a threshold level is obtained. The results are plotted on an audiogram.

Back 6

audiometer

Front 7

the frequency difference between the lower and upper noise band limits. More generally, however, the ______ of any device or system is the range of frequencies within which the performance of the device or system remains above a specified level.

Back 7

bandwith

Front 8

a periodic sound wave that consists of a fundamental frequency combined with other sine wave components at different frequencies

Back 8

complex tone

Front 9

occurs when the air particles are pushed together; this condition increases the resting air pressure

Back 9

compression

Front 10

the property of a medium or a body that enables it to return to its original shape after it has been deformed; may be considered a restoring force; the greater the _______ the more resistant the medium or body to deformation

Back 10

elasticity

Front 11

the number of complete cycles that a periodically vibrating source passes through in a 1-second time period; is expressed in Hz

Back 11

frequency

Front 12

the lowest frequency component in a complex tone

Back 12

fundamental frequency

Front 13

pure tone components of a complex tone that are integral multiples of the fundamental frequency

Back 13

harmonics

Front 14

a complex sound wave that consists of a fundamental frequency together with other pure tone components at integral multiples of the fundamental

Back 14

harmonic series

Front 15

the unit of measurement for frequency; named in honor of an important German physicist- Heinrich ______. It is synonymous with the formerly used expression cycles per second (cps)

Back 15

Hertz

Front 16

The ability of a body to continue doing what it has been doing; If the body is at rest, it will tend to remain at rest. If the body is in motion, it will tend to remain in motion

Back 16

inertia

Front 17

the condition in which two waveforms of the same frequency coincide exactly in their phas angles (phase difference). That is, both waves correspond exactly in their minimums and maximums at the same instants in time

Back 17

in phase

Front 18

the amplitude of a vibratin source at any instant in time

Back 18

instantaneous amplitude

Front 19

the amount of acoustic energy that passes through a unit of area in a given time span. May be measured in units of power or pressure directly, but more frequently it is measured in decibels, which are logarithmic ratios

Back 19

intensity

Front 20

noise that is restricted in its frequency range. The spectrum is continuous (no gaps), and the frequency components are all of equal amplitudes. Like white noise, there is no regard to phase of the pure tone components

Back 20

narrowband

Front 21

any undesired sound

Back 21

noise

Front 22

those frequencies below or above which there is no apprecialbe noise energy. In practice, the band limit frequency is often taken as the point where the energy content is 3 dB below the average energy in the pass band

Back 22

noise band limits

Front 23

the maximum instantaneous displacement of a vibrating source from its point of rest

Back 23

peak amplitude

Front 24

the amplitude of a vibrating source, measured from the maximum positive peak to the maximum negative peak

Back 24

peak-to-peak amplitude

Front 25

the time it takes to complete one cycle of vibration. is defined as 1/f, where f is the frequency of vibration. The ______ of a 1000 Hz tone is then 1/1000 or one one-thousandth of a second

Back 25

period

Front 26

vibration that repeats itself regularly over time; both pure tones and complex tones are examples of this

Back 26

periodic vibration

Front 27

that portion of a cycle (Hz) which has elapsed at a given instant in time, relative to some arbitrary starting point. Because of the relation between simple harmonic motion (SHM) and projected circular motion, the phase angle may vary between 0 degrees and 360 degrees

Back 27

phase angle

Front 28

the difference inphase angles between two periodic waveforms at any instant in time; relative to some arbitrary starting point. For example, if two 1000-Hz tones are started one-fourth cycle apart, their _____ __________ will be 90 degrees

Back 28

phase difference

Front 29

the condition in which two waveforms of the same frequency are exactly one-half of a cycle (180 degrees) out of ophase. That is, when one wave is at its maximum value, the other is, at teh same instant, at its minimum value. Thus, the two waveforms always assume opposite but equal positions relative to the baseline

Back 29

phase opposition

Front 30

a sound with a definite tonal quality. The waveform of the vibrating body that produces this is a sine wave. The frequency of this represents the completed number of cycles the vibrating source passes through in a 1-sec time period

Back 30

pure tone

Front 31

occurs when air particles are separated. this condition results in a decrease in the resting air pressure

Back 31

rarefaction

Front 32

represents the effective amplitude of the source. mathematically, this is equal to the square root of the mean of all the squared instantaneous amplitudes. For the case of a sine wave, this equals .707 times the peak amplitude

Back 32

root-mean-square

Front 33

a symmetrical to and fro motion of a body over a rest position. When the amplitudes of the body are plotted as a function of time, the resulting pattern is a sine wave. Pure tones are produced by this

Back 33

simple harmonic motion

Front 34

an instrument that measures sound levels in decibels with a specific reference of .0002 dyne per cm squared; it consists of a microphone, amplifier, output meter or digital display, adn several frequency-weighting networks. The purpose of the networks is to simulate the response characteristics of hte normal human ear

Back 34

sound level meter

Front 35

a plot showing the frequencies and amplitudes of the individual components of the wave. It is also used to denote a range of frequencies that possess a common characteristic, such as the audio-frequency spectrum

Back 35

spectrum

Front 36

a spectrum in which the energy in the wave is at only one or more discrete frequencies (a pure or a complex tone)

Back 36

line spectrum

Front 37

a spectrum in which there is a continuous and unbroken band of frequencies

Back 37

continuous spectrum

Front 38

the character of a musical tone that distinguishes one musical instrument from another; it depends upon the relative intensities of the harmonic frequencies produced by each instrument

Back 38

timbre

Front 39

a plot that shows the instantaneous amplitudes of the signal over time

Back 39

waveform

Front 40

consists of a continuous spectrum across the auditory range. Although the amplitudes of all the frequency components that comprise the noise are equal, there is no regard to the phases of the frequency components

Back 40

white noise

Front 41

the distance in space between two corresponding points (phases) in two consecutive cycles in a periodic sound wave; it is related to the velocity of sound and frequency by the formula "wavelength = velocity/frequency"

Back 41

wavelength

Front 42

graphic representation of a signal

Back 42

sine wave

Front 43

process whereby friction causes sound to weaken and eventually stop vibrating in a medium

Back 43

damping

Front 44

more than 1 wave together

Back 44

complex wave

Front 45

unit value used to measure sound

Back 45

dyne

Front 46

logarhythmic scale used to measure sound

Back 46

decibel

Front 47

amount of intensity at an individual frequency

Back 47

audiometric zero