EP and BP Rhythm:Acoustic and Perceptual Evidence

Sónia Frota Universidade de Lisboa

Marina Vigário, Fernando Martins

EP and BP in the rhythm typology

• I. Correlates of rhythm in the speech signal Frota & Vigário 2001

• II. Language discrimination experiments Frota, Vigário & Martins in progress

– Goals: • Better understanding of the rhythmic ≠ EP / BP

• Clarify the status of ‘mixed’ languages

Background

• Traditional view → isochrony (σ, ´σ σ σ, µ )

• New approach (Dasher & Bolinger, Daues 1983, 1987, Nespor 1990)

– phonological & phonetic properties• syllable structure x y

• vowel reduction x y rhythmic ≠s

• intonation/stress x y

– acoustic correlates reflect p-properties (Ramus et al. 1999)

• syllable structure variety/complexity - ∆ C < ∆ C + - %V > %V +

• vowel reduction - ∆ V < ∆ V +

– Rhythmic continuum or rhythm classes? → perception

P-properties: predictions

• EP stress-timed– reduced unstressed

vowel system

– phonetic deletion [ö,u] long C clusters

– strong contrast ´σ / σ

– intonation lingers on stress

• More stress-timed– ∆C >BP, %V<BP, ∆V>BP

• BP syll.timed/mixed– less vowel reduction (no

centralisation [ö,�])

– vowel epenthesis syllable simplication

– weaker contrast ´σ / σ

– intonation // stress

• More syllable-timed– ∆C<EP, %V>EP, ∆V<EP

I. Correlates of rhythm Frota & Vigário 2001

• Materials • x

Domain of rhythm

• Intonational phrase (I)– sentence = I-phrase

• Why?– Lapses and clashes

– Weight effects (Pepperkamp 1992, Nespor 1999, G&N 1999, F&V 1999)

• Phrasing variation due to speech rate (slower rate > more Is within a string)

• Sentence duration– EP < BP (*2corpora)

– Effect on ∆C and ∆V(Grabe & Low 2000)

Durational difference

• Effect on variability

– Intervalduration x100 sentence duration

– standard deviation ∆%C and ∆ %V →EP/BP

Results: EP ≠ BP

• Distinguishing role is played by %V and ∆%C

Acoustic results and our predictions

• %V: EP<BP √

• ∆%C: EP>BP √

• ∆%V: EP>BP X– vowel reduction

1: shorter Vs > ∆ V 2.: no V ≈ ∆V, < %V

– intrinsic V duration more extreme ≠s in BP

– phonological phrase lengthening in BP

• Variation in ∆%V within EP

• Stress-timed EP/Syl.-timed BP

Results: EP and BP in the rhythmic chart

• EP: stressed (∆C) and syllable-timed (%V) mixed

• BP: syllable (∆C) and mora-timed (%V) lang. ?

Are mixed languages intermediate languages?

• If so, a rhythmic continuum (Dauer 1987, Nespor 1990, Auer 1991)

• If not, rhythmic classes– EP/BP results

(more languages?)

• Correlation %V, ∆C– One of them is enough

• Conflicting classifications– (At least) Both are needed

P-properties revisited

• Syllable types: syllable-timed languages– p-processes: BP

• coda loss

• vowel epenthesis

• > Generalisation of CV

– p-processes: EP• effacement of Vs

• > C clusters

• Signal cues – / C(C)V/

– p-processes

II. Language discrimination Frota, Vigário & Martins

• EP and BP allow us to test the perceptual weighting of %V and ∆C

– EP• %V plays the major role → EP ≠ stress-timed L

• ∆C plays the major role → EP ≠ syllable-timed L

• Both are equally decisive → EP ≠ stress-timed L EP ≠ syllable-timed L

• 2 experiments: EP/BP, Targeting 2 Languages

– Test the relevance of intonation

Methods

• EP/BP– source sentences: Rm

• 15-19 syllables each

• representative

– low-pass filtering 400Hz

– 2 conditions: with F0 without F0 (flat= mean F0)

– 16 pairs: 6xY=Z;10xY≠Z

– Y, Z: different speakers

– 29 subjects → naive

• Targeting 2 Languages– Dutch, Spanish: RMN

– EP, BP: Rm• 15 or 17 syllables

– low-pass filtering 400Hz

– 2 conditions• Praat

– 20 pairs: 4xY=Z (Du/Du; Sp/Sp); 4xDu/Sp; 4xPE/Du; 4xBP/Du; 4xEP/BP

– 30 subjects → naive

Methods

• The story told– Tigre (afro-asian) & Hua (indo-pacific)

– Task: Y,Z are from the same or from different Ls

• Training– 4 sentences of Tigre (EP, Du)

– 4 sentences of Hua (BP, Sp)

– 2 Y=Z pairs, 2 Y≠Z pairs

– both types, with feedback (5pairs; 8 pairs)

EP/BP: results

With F0

65,56,9

27,6

Task

# Prediction

* Task

Without F0

27,6

13,8

58,6

Task

# Prediction

* Task

Wave Sound Wave Sound

Wave Sound Wave SoundWave Sound Wave Sound

Wave Sound

Wave Sound

Wave SoundWave Sound

EP/BP: results

• EP and BP are discriminated

• F0 is relevant– task feasable

– better results

• EP, BP and other languages? Du, SP

Targeting 2 Languages

• Is EP like Du (Tigre) or Sp (Hua) or none?

• Is BP like Du or Sp or none?– EP

• %V → EP ≠ Du, EP = Sp

• ∆C → EP = Du, EP ≠ Sp

• Both → problem (inconsistent results)

– BP• BP ≠ Du, SP?

Targeting 2 Languages: Results

Targeting 2 Languages (+F0)

75

32,1

39,335,7

82,1

25

67,9

60,764,3

17,9

0

10

20

30

40

50

60

70

80

90

Same L SP&DU BP&DU EP&DU EP&BP

Language pairs

% r

es

po

ns

es

Same

Diff

Targeting 2 Languages

• Is EP like Du (Tigre) or Sp (Hua) or none?

• Is BP like Du or Sp or none?– EP is Hua

• %V → EP ≠ Du, EP = Sp is not Tigre• ∆C → EP = Du, EP ≠ Sp

• Both → problem (inconsistent results)

– BP is Hua• BP ≠ Du, SP?

F0 effect

Discrimination

0

10

20

30

40

50

60

70

80

Same L SP&DU BP&DU EP&DU EP&BP

Language pairs

% r

es

po

ns

es

TL(+F0)

TL(-F0)

Conclusion

• Acoustic evidence– EP ≠ BP (%V, ∆C)

– EP has mixed rhythm• stress (∆ C)&syll.(%V)

– BP has mixed rhythm• syll.(∆ C)&mora (%V)

– No problem to the rhythm class hypothesis

– Test the perceptual weighting of %V and ∆C

• Perceptual evidence– EP ≠ BP (62.9%)

– F0 is relevant (46.7%)

– EP, BP, Stress-timed L Syllable-timed L EP ≠ Du (64.3%)

– %V takes the lead

– EP

– BP

EP and BP Rhythm:Acoustic and Perceptual Evidence

Sónia Frota Universidade de Lisboa

Marina Vigário, Fernando Martins

Thanks to F.Ramus, L.Wetzels, T.Rietveld, G.Elordieta