Measurement of Sound

Question 1

waveform

Answer 1

a mathematical representation of alternating pulses of compressed and rarefield air (or other elastic medium), shown as a graph of amplitude versus time

Question 2

amplitude of waveform

Answer 2

correlates to loudness and can be measured as SPL (micropascals) or as Intensity Level (w/m^2) on a logarithmic scale (dB)

Question 3

time scale of waveform

Answer 3

measured in s or ms

Question 4

spectrum

Answer 4

a graph showing the amplitude of each component frequency of a complex periodic sound on a scale of Hertz vs. dB (SPL)
at particular time points, what is the amp? what is the freq?
a graph of pure tones (harmonics), each having a different frequency and amplitude

Question 5

octave

Answer 5

the doubling of frequency

Question 6

harmonic

Answer 6

pure tones
sound waves that compose the complex periodic sound of voicing
component waves with frequencies that are integer multiples of the fundamental frequency (F0)

Question 7

fundamental frequency (F0)

Answer 7

1st harmonic/lowest harmonic

Question 8

how is a spectrum calculated?

Answer 8

by Fourier Analysis

Question 9

Fourier Analysis

Answer 9

a mathematical formula that provides a way to tease apart the elements of a complex, periodic sound –> the frequencies of the component pure tones and their amplitudes

Question 10

amplitudes of the series of harmonics decreases at the rate of ______

Answer 10

12 dB/octave

Question 11

3 systems of speech production (and function)

Answer 11

respiratory: power source
phonatory: sound source
articulatory: sound filter

Question 12

Source-Filter theory

Answer 12

explains how the respiratory, phonatory, and articulatory systems work together to produce speech sounds

Question 13

power source

Answer 13

pulmonic (respiratory) system produces the controlled expiration that powers speech
also provides subglottal pressure

Question 14

sound source

Answer 14

powered by airflow from the respiratory system

the laryngeal system produces the vibrations that serve as the basis for voiced speech sounds/phonation

Question 15

sound filter

Answer 15

the supralaryngeal system can open and close to let air out in greater and lesser quantities, thus producing vowels and consonants

Question 16

ranges of occlusion

Answer 16

least occlusion = approximant
middle occlusion = fricative
greatest occlusion = stops

Question 17

filtering

Answer 17

alteration of sound by the supralaryngeal system

Question 18

supralaryngeal system

Answer 18

throat, mouth, nose

Question 19

formants

Answer 19

sound waves produced in the vocal tract as air flows through and reverberates or resonates within the various cavities
NOT produced, they are determined by vocal tract shape

Question 20

harmonics-amplitude relationship

Answer 20

harmonics with frequencies closest to the formant frequencies will be amplified as they pass through the vocal tract

Question 21

What is significant about the first 3-4 formants?

Answer 21

our ears are very sensitive to the first 3-4 formants because we use them to distinguish the different speech sounds

Question 22

______ sounds have more distinct formants than _______ sounds

Answer 22

VOICED sounds have more distinct formants than VOICELESS sounds

Question 23

_____ have more distinct formants than ______

Answer 23

VOWELS have more distinct formants than CONSONANTS

Question 24

What does a spectrum show us?

Answer 24

all the details of phonation and articulation in one graph

but NO TIME DIMENSION –> it is a sample of a sound at one instant in time

Question 25

What information does a waveform provide?

Answer 25

It allows us to interpret or calculate the sound source (aperiodic/periodic, burst/frication, voicing) and allows us to see how amplitude changes over time

Question 26

spectrogram

Answer 26

a graph that represents time (x-axis), frequency (y-axis), and amplitude as a function of darkness on a grayscale

Question 27

2 forms of spectrogram

Answer 27

wideband and narrowband

Question 28

wideband spectrogram

Answer 28

highlights formants which are the responses of vocal tract

tells us about articulation

Question 29

narrowband spectrogram

Answer 29

highlights harmonics

tells us most about phonation

Question 30

What does a wideband spectrogram show us?

Answer 30

articulation, glottal pulses, formants (allows us to interpret how articulation is changing), harmonics (if speaker is shrill), fundamental frequency (may be calculated from glottal pulses or harmonics)

Question 31

What does a narrorband spectrogram show us?

Answer 31

phonation, formants (less clear), harmonics (see how phonation is changing), fundamental frequency (may be calculated from glottal pulses or harmonics)

Question 32

pitch contour

Answer 32

close-up view of a frequency
x-axis = time (s)
y-axis = frequency (Hz)
*frequency is a scale of 0-350 Hz

Question 33

energy contour

Answer 33

x-axis = time (s)
y-axis = amplitude (dB)