exam 4 Flashcards
spectrography
method of identifying frequency, amplitude, and duration
axis of a spectrogram
vertical: frequency
horizontal: time
darkness: intensity
former uses for spectrogram
used by universities and labs
current uses for spectrogram
diagnosis/treatment in hospitals, university clinics, and rehab centers
CSL - allows speech to be acquired, analyzed, and displayed
types of sounds
voiced
voiceless
quasiperiodic
voiced sounds
-periodic sounds
-have repeating pattern of vibration
-have harmonics
-on spectrograph: voice bar, vertical striations, formants
voiceless sounds
-aperiodic sounds
-no repeating pattern or vibration
(sound made by air forced through constriction)
-no voice bar or vertical striations on spectrograph
quasiperiodic sounds
-have vibration of vocal folds and harmonics
-on spectrograph: voice bar, but no vertical striations
vowels on a spectrograph
characterized by first three formants- high levels of acoustic energy
(dark horizontal lines)
band is wide because harmonics are amplified near vocal tract formant
diphthongs on a spectrograph
steady state formant
transition
steady state formant
diphthongs
vowels that change resonance characteristics during production (2 vowels as 1 unit)
glides on spectrograph
do not show steady state due to being more rapid than diphthongs
extremely short and looks like formant transition between two sounds
liquids on spectrograph
characterized by more steady state formants- not made by changing tongue placement
characteristics of /w/ and /j/
/w/: lips rounded = lengthens the vocal tract & reduces frequency for all 3 formants
/w/ and /j/: F1 beings low and raises to F1 of following sound
F2 and F3 shift toward values of following sound
characteristics of /r/
retroflexed-lowers F3 bringing it closer to F2
characteristics of /l/
formants
360 Hz, 1300 Hz, 2700 Hz
characteristics of nasals
formants- intense
antiformants- weaker/damped energy
nasal mumur
produced by blocking off oral cavity momentarily (at lip, alveolar ridge, or velum) and lowering velum
nasal formants characteristics (intensity and frequency)
high intensity, low frequency
characteristics of stops
silent gap
release burst
formant transitions
voice onset time (VOT)
silent gap of stops
time in which articulators are forming blockage and oral pressure builds
voiceless stops- cannot be seen
voiced stops- band of low frequency
release burst of stops
burst of aperiodic sound following the silent gap and extends into high frequency
line is short because release of stop is transient 10-30 ms
voiceless stop bursts
longer because of aspiration (noise generated by turbulence as air moves through glottis when vocal folds are starting to close
STRONGER THAN VOICED
voiced stop bursts
do not show aspiration noice because vocal folds are already closing and vibrating
formant transitions
articulators move from point of constriction to more open position of the following sound
lasts 50 ms
slope of transition depends on:
place of articulation for the stop
vocal position of following sound
F1 formant of stop
vocal tract is constricted - complete closure because stops start with tight closure
F1 is always rising if the stop is followed by a vowel; if the stop is proceeded by a vowel, the formant transition falls to 0
F2 formant of stops
related to length of oral cavity and reflects movement of lip/tongue in backward/forward direction
F2 transition starting points
stops: 600/800 Hz
alveolars: 1800 Hz
velar back vowel: 1300 Hz
velar front vowel: 2300-3000 Hz
VOT of stops
time release between release of articulatory blockage and beginning of voicing the following sound
depends of place of articulation
not as important in signaling voicing distinction in the final position as initial position
4 categories of VOT
negative
simultaneous
positive with short lag
voiceless stops with long lag
negative VOT
vocal folds were vibrating before articulatory release begins
prevoicing VOT lead- occurs in voiced stops
not common in english
simultaneous VOT
voicing and articulatory release occur at the same time
(VOT- 0)
positive with short lag VOT
onset of vocal fold occurs shortly after release burst
voiceless stops with long lag VOT
vocal fold vibration is delayed
voiced stops: -20 - 20 ms VOT
voiceless stops: 25 -100 ms VOT
VOT depends on:
place of articulation
increases as it moves backward in oral cavity
bilabial (shortest) — alveolar (intermediate) —- velar (longest)
vowels are _____ before voiced and _______ before voiceless
longer before voiced
shorter before voiceless
fricatives
produced when pressurized air becomes turbulent resulting in randomized variations in air pressure
fricatives of spectrograph
wide band of energy distributed over broad range of frequencies due to energy being much longer (fricatives are continuous)
have voice bar and periodic energy imposed on turbulent noise=combination of period and aperiodic sound
range of frequencies and intensity of friction depends on
place of articulation- airflow comes against obstacle that increases amplitude of noice produced at point of constriction
white noise
period with fairly distributed energy
fricative noise is resonated most strongly:
in front cavity (area in front of location of narrow channel-constriction)
anterior frictatives
/f/ /v/ and voiced/voiceless “th”
nonstridents
low intensity spectrum spread over broad range of frequencies
posterior fricatives
/z/ /s/ “zh” and “sh”
stridents
have larger cavity and lower frequency the further back it is
have higher frequency than anterior fricatives
affricates
combination of stops and fricatives
have acoustic element of both
characteristics of affricates
have a silent gap for stop portion if voices, but not heard in connective speech
fricative portion follows silent gap
fricatives vs affricates on spectrograph
they look similar, but affricates are shorter in duration
