Handout 5: Vocal Acoustics

Question 1

opening and closing of the VFs during phonation results in a generation of a complex periodic sounds w a certain ____ ______

Answer 1

fundamental frequency

Question 2

fundamental frequency is

Answer 2

lowest freq of a periodic waveform

Question 3

what does Hz represent

Answer 3

cycles per second

Question 4

the frequency of a waveform can be determined by

Answer 4

• the period is inversely related to freq
• need to measure the duration of a single cycle of vibration (peak to peak measurement)

then you need to divide 1000 ms by the durtion of the period, lets say its 10 ms

1000 ms / 10 ms = 100 Hz aka 100 cycles per second

Question 5

frequency

Answer 5

of cycles per second (Hz)

Question 6

pitch

Answer 6

quality of sound governed by the rate of vibrations - inc freq, inc pitch

Question 7

Praat is an example of a…

Answer 7

automaic pitch detection program

have been developed to automatically and continuously measure pitch periods over long periods of speech

no program or algorithm is 100% accurate; abnormal voices can be very difficult to measure pitch

Question 8

average fundamental frequency is

Answer 8

F0 average over the duration of a speech task or sample of connected speech

Question 9

average fundamental frequency by age and gender…

Answer 9

infants - 350-400 Hz
children - 270-300 Hz
young F - 220 Hz
young M - 120 Hz
Older F - 180 Hz
Older M - 140 Hz

Question 10

frequency variability

Answer 10

emotion, stress, or accent on syllables, grammatical forms all contribute to prosody and F0 variability

Question 11

what does too much or little F0 variability indicate

Answer 11

may sound abnormal and indicate a voice prob

Question 12

F0 range is

Answer 12

the diff bw the highest and lowest F0 in a sample of connected speech

Question 13

frequency variability gender and age diffs

Answer 13

infants - 1200 Hz
Children - 150-200 Hz
YM - 65 Hz
YF - 95 Hz
OM - 78 Hz
OF - 100 Hz

Question 14

certain voice disorders can have a sig reduced F0 range called

Answer 14

monopitch

Question 15

during prolonged ____ the F0 range should be v low .. higher values indicate a prob with ____ _____

Answer 15

vowels
pitch control

Question 16

maximum phonational frequency (MPFR)

Answer 16

obtained while producing stepping or gliding tones

range from the lowest to the highest tone that a person can sustain

Question 17

max phonational frequency range males vs females

Answer 17

males = 600 Hz range
females = 850 Hz range

Question 18

trained singers will have a ____ MPFR and those with voiced disorders may have a ____ MPFR

Answer 18

Wider
narrower

Question 19

speech amplitude is largely determined by …

Answer 19

the amplitude of sound that is created by phonation - speech and voice amp is roughly equivalent

Question 20

average amplitude level

Answer 20

• very dependent on speech activity/context
• measured by taking the average value over the duration of a speech sample

Question 21

average amplitude level of a normal average conversation is

Answer 21

68-70 dB at 12 inches

Question 22

age gender effects for average amplitude?

Answer 22

lower for children, women slightly less than men, older = younger

Question 23

amplitude variability

Answer 23

amplitude variations due to emotions, stress, or accent on syllables, grammatical forms

Question 24

what is the standard deviation of amplitude on neutral sentences

Answer 24

about 10 dB SDofA

Question 25

what is monoloudness

Answer 25

when people w voice disorders show reduced range/SDofA

Question 26

dynamic range

Answer 26

softest phonation to max loudness of phonation - about 50 dB to 115 dB

Question 27

when is there concern about dynamic range

Answer 27

if its less than 30 dB in the midrange of F0

Question 28

what is a voice range profile or phonetogram

Answer 28

dynamic amplitude plotted across F0 range

Question 29

what are cycle to cycle variations

Answer 29

an estimate of the average variation in each adjacent cycle of vocal fold vibration

Question 30

jitter

Answer 30

average cycle to cycle vibration in the time (period/freq) of vibration

Question 31

normal jitter is

Answer 31

less than 1% or less than 0.1 ms

Question 32

Shimmer

Answer 32

average cycle to cycle variations in the amplitude of vibration

Question 33

normal shimmer value

Answer 33

0.5 dB

Question 34

harmonics to noise ratio

Answer 34

the ratio bw periodic and non periodic components of speech sounds - i.e. desired signal to the level of background noise

the amplitude of the voice signal at the specific frequency of F0 and all of the related harmonics are determined and this harmonic amplitude is divided by the amplitude of other non F0 harmonic frequencies (vocal noise)

Question 35

what are the non F0 harmonic frequencies considered to be in the HNR

Answer 35

vocal noise

Question 36

what will a normal voice have for HNR

Answer 36

relatively small amplitude of vocal noise frequencies relative to the high amplitude of the F0 harmonic signal frequency

about 15-20 dB

Question 37

a ____ HNR is associated w a poor voice, ____ with a normal voice

Answer 37

lower, higher

Question 38

voice problem will have a HNR below ____

Answer 38

15 dB

Question 39

cepstral peak prominence (CPP)

Answer 39

• another measure of intensity/amplitude/prominence of vocal harmonics relative to the vocal noice
• involves second freq analysis - freq is called quefrency
  – createds a new plot called a cepstrum
• original harmonics appear as prominent peak relative to surrounding vocal noise

Question 40

CPP values obtained from prolonged “ah” that are ____ are abnormal

Answer 40

below 15 dB

Question 41

4 ways to measure voice quality

Answer 41

jitter
shimmer
HNR
CPP