phonation and stops CGSC433 exam 3

phonation refers to

additional distinctions that can be made by the glottal sound source

different phonation patterns are possible for any

manner of consonant or vowel

voiceless of aspirated state of the glottis

vocal folds wide open, allowing air to pass through freely

examples of voiceless or aspirated sounds in English

[p], [t], [k], [f], [s]

voiced AKA modal phonation

vocal folds vibrate normally

in English certain consonants

including [b], [v], [d], [g], [z], [m], and [n] and all vowels are generally voiced

voiced sounds produce

periodic wave which creates regular increases and decreases in pressure

breathy voice/murmur

vocal folds vibrate, but are held more loosely open, flap as air rushes by

creaky voice

one end of vocal folds is closed completely, while a small opening in the front is opened; it vibrates slowly and produces a low frequency sound

creaky voice has

slow, irregular vibration

creaky voice is also known as

vocal fry

open quotient refers to

the proportion of a cycle in which the glottis is open

creaky:

glottis is closed- the vocal folds are held loosely closed most of the time in the course of one cycle

breathy:

glottis is open (the vocal folds vibrate, but without much contact) most of the time in the course of one cycle

modal

glottis is open and closed for approximately equal amounts of time in the course of one cycle

the acoustic correlates are best viewed from

a spectrum, which is not LPC smoothed in order to see the harmonics

the difference between the amplitude of the 1st and 2nd harmonics can be

a good indicator of the phonation type

Amplitude of H1>H2

breathy

Amplitude of H1=H2

modal

amplitude of H1

creaky

unlike vowels and fricatives, stops cannot be characterized by

a snapshot of the vocal tract at some point in time

stops are dynamic and characterized by a sequence of particular events in time

1. shutting 2. closure 3. release (which involves transition)

sources of sound in stops

shutting, closure, release

in the shutting stage

there may be some type of voicing- modal, creaky, breathy

preglottalized stops

creaky

pre-aspirated stops

breathy

during closure only possible source is

voicing, otherwise closure is voiceless

audible aspiration is

unlikely since walls of vocal tract muffle turbulence produced during closure

often see voicing in the spectrogram at

the beginning of closure, but can fade away towards end of closure

it is hard to maintain voicing with

lack of airflow past closure

the release begins with

a burst, a very short transient noise, produced when air pressure behind the closure is suddenly released

following the burst there may be

voicing- modal, creaky, or breathy or aspiration in the release

sources of sound in aspirated stops

burst noise, and aspiration noise

burst noise is

very short and produced at place of articulation

aspiration noise can be

very long and produced at glottis

[p/b, t/d, k/g] are distinguished by

voicing

stops build pressure above

larynx

voice onset time (VOT) is

start of vocal fold vibration relative to stop release

stop + vowel prevoicing languages

French and Russian [b, d, g]

stop + vowel unaspirated languages

French and Russian [p, t, k] and German and English [b, d, g]

stop + vowel aspirated languages

German and English [p, t, k]

few languages distinguish

three levels of voicing

what language distinguishes three levels of voicing

Thai, pre-voiced, unaspirated, and aspirated

most languages distinguish

two levels of voicing- voiced/unvoiced

in the process of shutting and releasing

the vocal tract configuration filters the source as it does for vowels

the sound source is located at the

glottis and must pass through the rest of the vocal tract

location of stop constriction (place of articulation) determines

shape of the vocal tract

stops differ in

where they block flow

when stops are released they go through

a transition phase in between the stop and the vowel

from stop to vowel

1. shutting 2. closure 3. release burst 4. transition 5. "steady-state" vowel

from vowel to stop

transition, closure, then release burst if any

transition into obstruction F1 transition is usually towards

low frequencies

stop components from Armenian

when the spectrogram was first invented phoneticians figured out quickly how

to identify vowels from their spectral characteristics but it was much harder learning how to identify stops by place of articulation

the formant transitions F2 and F3 between vowels and stops

provide a reliable cue to place of articulation

the resonant frequencies of the vocal tract change during

entrance or exit from closure phase

formant frequencies usually decrease near

bilabial stops

from front vowels into alveolars

F2 tends to slope downwards

from back vowels into alveolars

F2 tends to slope upwards

the value transitions for alveolars tend to point to the same

frequency value- 1800 Hz

1800 Hz for alveolars is known as

the locus of the formant transition

in the 1950s researchers theorized that the locus frequency can be used by

listeners to reliably identify place of articulation

F2 and F3 often come together in

velar transitions-velar pinch

velars are a problem for

"locus theory" of perception

velars exhibit a lot of

co-articulation with neighboring vowels

fronter- more palatal next to front vowels

locus is high-1950-2000 Hz

backer more velar next to back vowels

locus is lower <1500 Hz

velar co-articulators