Nasals and Liquids CGSC433 exam 3

what's the source of sound for nasals

voicing

how is the sound for nasals generated at the source filtered by the vocal tract?

the filter-vocal tract configuration is more complex than for vowels, with not only tubes that are acoustically coupled but also with tubes that branch

for nasals the velum is

lowered which creates an open pathway from pharynx to nasal passages which allows air to flow from lungs out through nostrils

nasal consonants: mouth cavity is

closed off by a complete constriction in the vocal tract either at the lips, alveolar ridge, velum, etc.

nasalized vowels

both mouth and nasal cavities are open to the outside

uvular nasal [ɴ] can be modeled as a

single tube closed at the glottis and open at the nostrils

with the uvular nasal [ɴ] the oral cavity is

blocked off by closure produced by the uvula and tongue body

resonances for nasals have

lower frequencies and are closer together (about 800 Hz apart) than for a neutral vowel like schwa

nasal resonances are

weaker- peaks are lower in amplitude due to damping

when an input of energy sets a body vibrating the resulting vibrations

die out as energy is dissipated through friction, transmission of energy to surrounding air, etc.- wave is damped

damped wave

all speech sounds are

damped somewhat

standing waves in the vocal tract are damped due to

friction, radiation losses to the outside air, absorption of energy by the elastic vocal tract walls, etc.

the walls of the vocal tract are

soft and absorb some of the sound energy produced by the glottis

greater surface area results in

more damping and broader formant bandwidths

nasals have more damping because

the pharynx, nasal cavity, and oral cavity are all involved, nasal passages have small side cavities which further increases surface area and hence damping

illustrations of nasal cavities

damping

increases spectral bandwidth- widens the span of the peaks

since energy distribution is over a wider range of frequency

spectral peaks are also lower in amplitude

nasal consonants made with an

oral constriction further forward than the uvula add a side cavity- the oral cavity onto the pharyngeal nasal tube

the further front the constriction

the longer the side cavity

the side cavity is a

tube open at one end

the side cavity doesn't open to

the atmosphere at the mouth end so the resonating frequency components are not transmitted out of the vocal tract. Instead they're absorbed by the side cavity

frequencies that are absorbed in the side cavity are called

anti-resonances and anti-formants because they are cancelled out, so they show up in the spectrum as valleys rather than peaks

the further forward the place of articulation

the lower the anti-formants are

nasal murmurs

don't provide strong cues to place of articulation on their own

listeners can only distinguish between the nasal murmurs in [m] and [n]

72% of the time

transitions provide

the best cue for place of articulation especially transition from nasal to following vowel

95% of nasals are identified correctly when presented with

first 10 ms of the following vowel

nasalized vowels involve

a complex vocal tract configuration

the coupled nasal cavity contributed

both formants and anti-formants which combine with the formants of the oral tract

the net acoustic effect of velum lowering depends on

the formant frequencies in the corresponding oral vowels and as a result it is difficult to give a general acoustic characterization of nasalization on vowels

nasal vowels are

less distinct from each other than oral vowels both in terms of confusability and similarity judgements

the greater confusability is reflected in the fact that

in languages with contrastive vowel nasalization, the nasal vowel inventory is always the same or smaller than the oral vowel inventory, never larger

-pin-pen and him-hem are

homophonous

pit-pet

contrast

vowels are substantially

nasalized before nasals in English

nasalization

reduces the distinctiveness of F1 contrasts

oral [ɪ]-[ ɛ] are

sufficiently distinct

addition of the lowest nasal formant in combination with broad bandwidth F1 can create

a broad, low frequency prominence- can make height of vowels harder to distinguish

due to increasing formants and anti-formants and acoustic consequences of nasal vowels

they are much more difficult to model and predict than for oral vowels

what's the source of sound for laterals

voicing

how is the sound for laterals generated at the source filtered by the vocal tract?

with not only tubes that are acoustically coupled with one another end to end, but also with tubes that branch

lateral articulation

laterals look

somewhat like nasals in a spectrogram too

like nasals the laterals formants are

broader and less intense than vowels

unlike nasals the laterals formants are

further apart (more vowel-like)

laterals are usually

more intense than nasals

laterals have less

surface area=less damping

the break between vowels are laterals is

less clear

laterals like nasals have

a "side" cavity that introduces an anti-formant in the output spectrum

the "side" cavity is

the pocket of air on top of the tongue

the main cavity

curves around one or both sides of the tongue

main cavity

tube closed at glottis, open at mouth

"side" cavity

also closed at one end (place of constriction), open at the other (pharynx)

rhotics are

much more complex

there are many different kinds of

rhotics and there is no clear way of unifying them phonetically which makes it incredibly difficult to model

trills, taps, bunched/retroflex [ɹ] show

very different aocustic/articulatory characteristics

Lindblom (1985)'s model of rhotic parameter relations

[ɹ] typically combines three different approximant constrictions

alveolar/post-alveolar (retroflex), lip rounding (labialization), and pharyngeal constriction (pharyngealization)

english speakers make the [ɹ] constriction in two different ways

tongue bunching and tongue curling (retroflex)

how are [l] and [ɹ] primarily distinguished?

F3

[r] has a

much lower F3 than [l]

[l] usually has a

lower F2 in English

nasals and laterals are

less intense than vowels

nasals and laterals can be modeled as

a tube model with a branching side cavity

we can model both main tube and side tube as

tubes open at one end producing formants and antiformants

resonant frequencies of the side cavity become

antiformants and are viewed as valleys, instead of peaks in the spectrum

the further forward the constriction in the oral cavity

the lower the antiformants

nasalized vowels are much more

complex due to both nasal and oral cavities being open to outside air, and coupling of formants/antiformants

rhotics are difficult to model because

of their varied articulations

important characteristic of English [ɹ] is

lowered F3 in part due to lip rounding

many things affect the suprasegmental properties of segments such as F0, duration, intensity/amplitude/loudness) including

prosody, position in word or utterance, local context, and intrinsic properties of vowels or consonants

interaction between stress and vowels is

highly language specific

languages with little to no vowel reduction

Spanish and French

languages with phonetic reduction

English

languages with neutralization

Russian

hyperarticulation localized to

stressed syllables- greater range/velocity of articulatory movements

articulatory consequences of hyperarticulation

greater range of movement, greater movement of velocity, greater duration of movement, resistance to coarticulation

absence of consistent phonetic correlates of stress also means

stress is a perceptual phenomenon

factors that influence duration

intrinsic properties of gestures, lengths contrasts, local context, prosodic structure

universally lower vowels are

longer than higher vowels

universally labial stops are

longer than coronals or dorsals

language specific- fricatives are

usually longer than stops

geminate consonants are

roughly twice the duration of single consonants

languages that have geminate consonants are

Italian, Japanese, Finnish, and Arabic

long vowels usually differ from

short ones in quality as well in Hungarian

universally vowels are shortest before

labials

almost universally vowels are shorter before

voiceless consonants than voiced

vowels are shorter before

stops than before fricatives

the greater the number of syllables in a word

the shorter each vowel is

the last vowel in a word is

the longest

vowels in stressed syllable are

longer than in unstressed syllables in many languages

vowels and consonants are longer

at the end of phrase than within phrase

gestures are slowed down near

phrase boundaries

F0 is often higher for

vowels in stressed syllabes

higher F0 in segments at

beginning of phrase

if a language distinguishes tone

massively effects F0 of segments

high vowels>

low vowels

voiceless stops and fricatives >

voiced stops and fricatives