linguistic stress in language and speech

Linguistic Stress in Language and Speech

Kenneth de JongIndiana University

Chapter N+1. Suprasegmentals

• The last chapter in phonetics descriptions• Consists of Tone, Stress, Quantity, may-be

juncture• Or … fundamental frequency, loudness,

duration, may-be syllable stuff• What do these have in common?

Chapter N+1. Suprasegmentals

• Scary• When doing basic transcriptions, we can sorta skip them -- e.g.

no tonal minimal pairs.• … in English … (most languages have tone contrasts, most

languages have quantity contrasts)• Tend not to fit well with a segmental model of phonetic structure.• Vary with spoken context. Intonation is a property of the

sentence; duration varies overall by tempo; …• Tend not to be as well understood (linguistically) as things like

‘aspiration’, ‘point of articulation’, & ‘vowel quality’

Stress

• What is it?• Why is it?• What does it tell us?

What stress is: phonetic observations

• OK, we do need it in transcriptions: ‘deepened’ vs. ‘depend’

• D.B. Fry (1955, 1958, 1965): perception– F0 pattern (some complicated stuff about pitch)– Duration (longer)– Intensity (more intense)– Other stuff (vowel quality more extreme)

• Stress vs. Accent: making sense of context– Accent: F0 pattern varies qualitatively by context, e.g.

statement vs. question – Other stuff more attached to the word itself

What stress is: Phonological observations

• Many languages have something similar to English stress– Cross-language studies, such as de Jong

& Zawaydeh (1998): Arabic is surprisingly like English

• Various patterns appear in a number of languages– Keeping track of them all creates things

like metrical phonology

What stress is:Metrical observations

• Reduced Contrast: Unstressed items can have fewer contrasts. • Domain: Stress is expressed over a syllable. • Alternation: Stressed and unstressed material tends to be collated. • Spacing: Stresses tend to be distributed evenly. • Accent Location: Stressed items often are the site for accents. • Culminativity: Stresses may bear a one-to-one relationship with a higher-level unit, such as a phrase. • Weight Sensitivity: Stresses tend to fall on heavy syllables;heavy syllables are ones with long vowels and sometimes consonantal codas. • Boundedness: Stress location is often fixed in relation to alocation within a word. • Boundedness Variation: Stress locations may either be determined by position in morpheme or by weight sensitivity.

What stress is:Characterizing the ‘other stuff’• Loudness vs. Clarity

• Loud people– Brits: Sweet (1892), Jones (1960): pulmonic force -> heard

as loudness– Americanists: Bloomfield (1933), Trager & Smith (1951)– More sophisticated: Lehiste (1970), Beckman (1986)

• Clear people– Brits: Walker (1781); Jones (1960): prominence = distinctness– Swedish research: Ohman (1967), Engstrand (1988)– American speech: Kent & Netsell (1971); Harris, 1978)

What stress is: Characterizing the ‘other stuff’• Loudness vs. Clarity

– Speech production work• Similarities

– Open up vowels– Close down consonants for contrast– Make it longer– Loudness is a way of being clear

• Differences– Care with respect to targeting– Being clear is harder than being loud

What stress is: Characterizing the ‘other stuff’• de Jong (1995)

– Compare production of words with /o/ in context of coronal consonants

– Use X-ray microbeam facility to see what’s going on inside– Found vowels with further tongue body retraction– Degree of retraction was not predicted by duration increases, so it

can’t be due to undershoot mechanisms• de Jong et al (1993)

– Consonant coarticulation• de Jong (1998)

– Looked at articulation of post-vocalic /t/ & /d/ with stress variation– Find variation due to something like ‘degree of effort’

Illustrative Results

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

Tongue tip movement patterns for phrase:

‘Put the t__ …’.

Solid = unstressed ‘Put’,

Dashed = stressed ‘Put’

What stress is:Hyperarticulation

• “Clarity”, sweet clarity• Connected to ‘Hyperarticulation’ (Lindblom, 1990)

– Speech production happens in a sea of variability– Some of this is due to ‘mode of production’– Hypoarticulation = maximize production system

considerations– Hyperarticulation = maximize likelihood the other guy will

understand you• Hyparticulation local to the syllable (de Jong, 1995)• More attention in production (de Jong, 1998)

What stress is:Testing Hyperarticulation

• Lindblom: hyperarticulation = premium on getting information in signal

• Hyperarticulation happens in corrective focus: – “I said ‘bed’, not ‘chair’.”

• IF corrective focus => hyperarticulation & stress => hyperarticulation,

• THEN stress & corrective focus should have same effect as corrective focus.

• de Jong & Zawaydeh (2000) & de Jong (2004) test this with vowel duration and quality effects

de Jong (2004): results for voicing X vowel duration

• Words like ‘flowerbed

• ‘bed’ longer than ‘bet’

• Focus makes difference bigger


• Add words like ‘bed’ - primary stress

• ‘bed’ longer than ‘flowerbed’

• Stress & focus have similar effect

• Stress + focus get even larger effect


• Add words like ‘rabid’ and ‘rabbit’

• Much shorter• No voicing

difference• Get a tiny effect

with focus

Results, de Jong (2004)

• To Summarize– Both stress and focus increase duration– Both stress and focus increase duration

contrast - specified differences get bigger– Stress and focus interact so that contrasts

get much larger in focused & stress material

– Side note on stress shift

What stress is:General Attentional Model

• Other work on auditory attention in time (Jones, Kidd)• Various properties

– Attentional selectivity: some parts of a stimulus are more readily acted upon than others

– Attentional capture: parts which change in salient ways tend to garner selective advantages

– Attentional integration: aspects which work together to define an event get attended to as a unit

– Temporal expectancy: events forming regular temporal patterns will focus attention on particular up-coming times

What stress is:General Attentional Model

• Stress = some syllables are attentionally selected• The attentional selectivity arises from attentional capture by

acoustic events with sudden changes• And may exhibit attentional integration where bits of speech

which cohere and are regular form units• Attention modulation can be governed by temporal

expectancy, wherein high attention areas can come at regular intervals

• Attention modulation characterizes both hearer and speaker– Speakers put important stuff in high-attention areas– Hearers look for high-attention areas– The match between speaker and hearer is A Good Thing

What stress is:Phonological properties

• Reduced contrast: unstressed = low attention area = a bad place for information

• Domain: syllable onsets = places of sudden change => attentional capture; syllables tend to be unitary acoustic objects => attentional integration

• Alternation: since attention is relative, attending to one event detracts attention from neighboring events


• Spacing: temporal patterning, especially regular spacing in time, tends to make high attention areas occur at regular intervals

• Accent location: accents help direct attention to syllables which are hyperarticulated by the speaker

• Culminativity: if stresses are attentional objects, having one stress per meaningful unit would make a mechanism which allows speakers to present speech a series of meaningful tasks

…. Good so far …


• Weight Sensitivity: so … why DO syllables with a final consonant tend to get stressed?

• Boundedness: and why do stresses come in particular places in the word?

• Boundedness variation: oh yeah? if there are good places in the word for stress, why are different languages so different with respect to WHERE?

• Actually: if stress is so functional, Mr. Stress Man, why DO languages stress different syllables?

• Better take a good look at language differences …

Korean Case Study: Korean Stress Rule

• Korean stress rules– Polianov (1936): if at end of utterance, stress the first

syllable, otherwise stress the last one– Huh (1985) & Lee (1992): stress the first syllable always– Lee (1974, 1985, 1989): ‘Weight sensitive’ -> stress a long

vowel or an initial syllable with a coda, otherwise stress the second syllable

– Yu (1989): ‘Weight sensitive’ -> stress the first heavy syllable you come to, otherwise stress the last one

– Lee (1990), Kim (1998): ‘Weight sensitive’ -> stress a heavy first syllable, otherwise stress the second syllable

– Zong (1965), Cho (1967): ‘Unbounded’ -> it’s unpredictable so you just memorize it.

Korean Case Study: Lim (2000)

• Lim’s Expectations


• Lim’s Expectations– Stress heavy first

syllable


• Lim’s Expectations– Stress heavy first

syllable– Stress light second

syllable


• Lim’s Results– No systematic

differences by position– No effect of weight on

position


• Production Results– No systematic differences in vowel durations, except that

vowels at the end are longer– Syllable weight makes no difference

• Compares with Balinese production studies (Barber, 1977; Herman, 1998)– Barber is a very reliable and experienced field worker who

relied on impressionistic transcriptions– Herman ran acoustic measurement studies– No systematic differences in vowel durations, except that

vowels at the end are longer– Syllable weight makes no difference

Balinese Case Study: Herman (1998)

• Barber (1977), first:"There is no strong word-stress in Balinese in

ordinary speech, there is only a slight variation in loudness and energy between the syllables of a sentence.”

• Barber (1977), then (same page later on):

"In words of more than two syllables (not counting suffixes), the penultimate syllable is stressed unless the vowel is e."

Balinese Case Study: Herman (1998)

• Herman (1998), her comment:

"It is theoretically impossible to prove that some entity does not exist. Therefore, it is impossible to prove that word-level accentuation does not exist in Balinese. However, if word-level accentuation in some form did exist, one might expect to find certain indications of it."


• Production Results– No systematic differences in vowel durations,

• Summary– KOREAN DOESN’T HAVE STRESS– Korean Intonation Tutorial

http://www.linguistics.ucla.edu/people/jun/ktobi/K-tobi.html


• Point: Though a stress system might be functional, languages work perfectly well without them.

• One more question: so what do we hear as stress when listening to non-stress languages?


• Perception Results - ask them to locate stress– Korean listeners tend to say stress occurs in the vicinity of a pitch

peak– Pitch rises and falls in Korean are used to mark the edges of words

• Perception Results - suggests weight sensitivity– The presence of consonants determines where, exactly, pitch

peaks show up– If stresses ‘grow out of’ locations for pitch peaks, then consonants

can indirectly determine where stresses get located– This can explain weight sensitivity– This explanation doesn’t directly use attentional selectivity to

consonants.

Why is stress?

• The functional nature of attention modulation. It has to do with the dynamics of speaker’s production systems and/or the dynamics of hearer’s perception systems and their linkage.

• The not particularly functional nature of language history. It has to do with the (much slower) dynamics of language groups.

What does it tell us: • The functional nature of stress

– Plasticity in production: people are more skilled then they are given credit for.

– Acquisition patterns: not all segmental material is created equal.

– Fluency complexity: speech takes place in a sea of variability.

• The not particularly functional nature of language history. – Cross language differences and bio-physical explanations– Second language acquisition

de Jong (2004): results

linguistic stress in language and speech

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