Week 7 – Syllables and Sequences

Mark Huckvale

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Last Week

• Phonological choices can be determined by finding minimal pairs

• There are about 24 consonant choices in English which can be classified according to their typical articulation

• Consonants are described using the Voice-Place-Manner system

• Approximants and Nasals have similar acoustics to vowels

• The source of energy for fricatives is turbulence generated at or near the constriction. Fricative spectra vary according to size of cavity forward of the constriction

• Plosives have a series of events: closing, hold, burst, opening, and optional aspiration. Place cues for plosive are related to the spectrum of the burst and the formant transitions

• Voice Onset Time is an important voicing cue for plosives

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Syllable Structure

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古池や蛙飛込む水の音 ふるいけやかわずとびこむみずのおと furuike ya kawazu tobikomu mizu no oto The old pond, yes, and A frog is jumping into The water, and splash.

Matsuo Bashō (松尾 芭蕉)

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Parts of Syllables

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Structure Example Structure Example Structure Example

V a

CV pay CVC pit VC art

CCV pray CCVCC plinth VCC ask

CCCV spray CCCVCCC splints VCCC asked

CCCVCCCC strengths

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English Syllables

Onsets

• in C1C2C3, C1=/s/

– /stretʃ/, not /ʃtrets/ • /w, r, l, j/ always adjacent

to vowel

• plosives and fricatives outside nasals and approximants

• no /ŋ/, no /ʒ/

Codas

• in VC1C2C3C4, C4=/s/

– /leŋkθs/, not /leŋksθ/ • no /w, j/, /r/ only in rhotic

accents

• plosives and fricatives outside nasals and approximants

• no /h/

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Combining Syllables

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Stress Prominence

• Lexical stress

– “Over", “SUPper", “CHIna", “BROken"

– "aHEAD", "beFORE", "supPOSE" and "caREER“

• Stressed syllables tend to be:

– spoken more slowly

– spoken more carefully

– targeted for pitch movements

English Word Stress

• One syllable

– may or may not be stressed

• Two syllables

– usually first is stressed (lots of exceptions)

• common, nation, open, study, sorry

• More than two syllables

– usually antepenultimate (lots of exceptions)

• universe, article, relative, democracy, economy

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Lexical Stress in Phrases

• When words combined into phrases, lexical stress pattern can alter – “afterNOON”, “AFTernoon TEA”

• Causes include – when words form compounds

• “black board”, “long island”

– to preserve rhythm/avoid sequence of stressed syllables • “THIRteen COMpanies”, “JAPanese INstitute”

• Hard to predict!

Articulation of sequences

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Phonology – Phonetics - Acoustics

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Phonology – Underlying Segment Sequence

Phonetics – Movement of Articulators

Acoustics – Generated Sounds

Segments as Targets

Vel

um

Hei

ght

s ɪ n s

Articulator trajectories

Some simple dynamics

mass

spring

force

position

time

trajectory

Effect of Damping

A A B B

target

undershoot

sufficient time to reach target

insufficient time to reach target

Undershoot

Articulatory Measurement

Lower lip

Tongue tip

Tongue blade

Tongue dorsum

Consequences

• Speaking sequences of speech sounds - involving multiple articulators each with different dynamical properties - is going to take a lot of planning.

• We need to allow sufficient time for each articulator to reach its target location and we need to ensure that the slower moving articulators are in position for when they are needed to synchronise with the faster moving articulators.

• Articulatory planning to allow rapid articulation causes contextual effects, these are changes to the articulation of phonological segments depending on the context

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Contextual Effects

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Contextual Effects

n-2 n-1 n n+1 n+2

time now

context carried over context anticipated

sequence of events

• Contexts include: – Phonological segment sequence

– Position in syllable

– Stress, rhythm, intonation

– Speaking rate

– Speaking style

Coarticulation

• Coarticulation = Joint articulation – when same articulator is used for adjacent

segments

– compromised articulatory position

• Anticipation – “car”, “key”

– “heed”, “hard”

• Carry-over – “please”

Vowel – Nasal – Fricative ɑː n s

tongue height

velum height

vocal folds

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Assimilation

• Contextual effects in planning that involve more than one articulator

• Makes underlying phonological sequence ambiguous to listener

– “good boy”, “good girl”

– “have to”

– “happen”

Assimilation in “good boy”

Elision

• Elision is when contextual effects appear to delete phonological elements

– “next week”, “don’t ask”

– “library”, “February”

• But elements may not be completely deleted

– “perfect memory” tongue tip gesture preserved

– “bookcase” gemination preserves timing

– “supporter” preserved syllable context

Browman & Goldstein , 1992

Contextual Effects Summary

• Coarticulation – Effect of multiple phonological segments on single

articulator (segments still identifiable)

• Assimilation – Blurring of phonological segments (segments

ambiguous)

• Elision – Loss of phonological material in phonetic form

(segments absent)

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Spectrograms of Connected Speech

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Continuity

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Continuity

• Speaking involves rapid, smooth, continuous movements of the articulators

• There are no explicit breaks in articulation between segments, syllables or words.

• Equally there are no explicit breaks in the spectrographic pattern between segments, syllables or words

• Pauses that do occur tend to be at phrase boundaries

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Summary

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Summary

• Syllables are intuitive units of speech planning • Languages place constraints on syllable structure • The dynamics of articulation mean that speech must

be planned to ensure appropriate sounds are produced at normal speaking rates

• Planning involves anticipatory and carry-over contextual effects: coarticulation, assimilation and elision

• The articulatory and acoustic form of phonological material depends on context

• There are no necessary acoustic cues to segment, syllable or word boundaries in the signal

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Lab Session

• Robo-Voice:

• Make new utterances by cutting up old ones

• Hear consequences of contextual change

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