Ch 4 (MIDTERM)

Question 1

Basic Trig

Answer 1

SohCahToa

Question 2

Starting phase

Answer 2

What phrase the object starts to vibrate
0,90,180,270,360

Question 3

Instantaneous phase

Answer 3

Point in displacement cycle at time of measurement

Question 4

Amplitude

Answer 4

Displacement of particles

Question 5

Instantaneous amplitude

Answer 5

Amplitude at a specific moment in time

Question 6

Peak amplitude

Answer 6

Max amplitude

Question 7

Peak-to-peak amplitude

Answer 7

Compression to rarefaction, peak to trough

Question 8

Complex tones

Answer 8

Multiple frequencies
Most common in speech

Question 9

Pure tones

Answer 9

Only made up of one frequency

Question 10

Periodic

Answer 10

Takes same amount of time for each cycle
When there is only one frequency, or the frequency make-up are harmonics of the fundamental frequency

Question 11

Aperiodic

Answer 11

Takes different amounts of time for each cycle
When there is no pattern to the frequencies in the sound, usually made up of ALL frequencies within a certain range

Question 12

Waveform

Answer 12

X=time, Y=amplitude
Looks like a wave

Question 13

Spectrum

Answer 13

Shows frequency content
Frequency makeup of complex sounds
x-axis is frequency, y-axis is amplitude or phase

Question 14

Line spectrum

Answer 14

A single line, usually harmonics (periodic) tone

Question 15

Continuous spectrum

Answer 15

Contains all frequencies within a range, usually complex aperiodic noise

Question 16

Amplitude spectrum

Answer 16

X axis = frequency
Y axis = Amplitude
Shows amplitude of each frequency in sound

Question 17

Phase Spectrum

Answer 17

X axis = frequency
Y axis = phase
Shows the phase at which each frequency starts

Question 18

Spectogram

Answer 18

3D representation of time domain, frequency Y-axis and shading shows intensity

Question 19

Sine waves/Simple harmonic motion

Answer 19

Periodic in nature
single frequency
looks like a sine wave
one line in amp spectrum
on dot in phase spectrum

Question 20

Summing pure tones of the same Hz

Answer 20

Add sine waves by summing the amplitude of vibration at each point in time

If 2 of the sine waves of same frequency at same phase: vibration/amplitude amplified, constructive interference

If 2 of the sine waves of same frequency at different/opposite phase: vibration/amplitude deleted, Destructive interference

Question 21

Summing different pure tones

Answer 21

Creates COMPLEX sound

Question 22

Beats

Answer 22

When 2 pure tones of equal intensity and slightly different frequency combine, causes sensation of listening to a single tone pulsating

Question 23

Harmonics

Answer 23

Created when summing 2 or more specific pure tones that are whole number multiples of the fundamental frequency

Harmonics: whole number multiples of the lowest tone (fundamental frequency which is not always the lowest number in a sequence)

usually, when harmonics of a fundamental frequency are in a sound, it creates a complex PERIODIC sound since it has structure to the frequency make up

Question 24

Octave scale

Answer 24

Doubling frequency is equal to 1 octave

Question 25

Distortion

Answer 25

Change in a sound due to inaccurate production/transmission/reproduction

Question 26

Fourier's Theorem

Answer 26

Any wave can be broken down into component parts Spectral analysis to analyze different frequency components

Question 27

Complex periodic waveforms

Answer 27

Either looks like a square, triangle, or saw-tooth (symmetrical) Has multiple lines in amplitude spectrum (of harmonics) has multiple dots in phase spectrum (of the same phase)

Question 28

Three types of complex periodic waveforms:

Answer 28

Square wave Triangular wave Saw-tooth wave

Question 29

Square wave

Answer 29

-6dB/octave Harmonics are ODD

Question 30

Triangular wave

Answer 30

-12dB/octave Harmonics are ODD

Question 31

Saw-tooth wave

Answer 31

-6dB/octave Harmonics are EVEN or ODD

Question 32

Complex Aperiodic

Answer 32

Waveform is chaotic One continuous line in amplitude spectrum Multiple random dots in phase spectrum

Question 33

Noise

Answer 33

Sound made up of ALL types of frequencies in a range APERIODIC (no consistency in frequency makeup) and Complex (more than 1 frequency)

Question 34

White noise (guaissian)

Answer 34

Continuous spectrum contains ALL possible frequencies of same average intensity

Question 35

Broad band noise

Answer 35

Contains ALL frequencies within a broad range

Question 36

Narrow band noise

Answer 36

Contains all frequencies within a narrow limit Usually a specific frequency used to cover up frequency that crosses over from insert phone during audiogram

Question 37

Pink noise

Answer 37

Less higher energy frequency, has a -3dB/octave slope

Question 38

Click

Answer 38

Transient signal Very short duration like the clicking of a pen used in ABR

Question 39

ABR (Auditory Brainstem Response)

Answer 39

Using surface electrodes to measure brain response to sounds Often not diagnostic, for screening purposes

Question 40

Specificity

Answer 40

Ruling out those who do not need further attention. If specificity is low, there are many false positives

Question 41

Sensitivity

Answer 41

Identifying who does need help If sensitivity is low, there are many false negatives