Exploring Boundary Tone Perception in German: Findings from the Stuttgart Project

1. Experiments concerningboundary tone perception in German 3rd Workshop of the SPP-1234 Potsdam, 7th January 2009 Presentation of the Stuttgart Project (Möbius & Dogil) Katrin Schneider

2. Outline • Categorical Perception (CP) • Perceptual Magnet Effect (PME) • Experimental designs • Stimulus preparation • Experiments: • Boundary tone perception in German without context information • Boundary tone perception in German including context information (Identification only) • Outlook

3. Categorical Perception (CP) • Test design developed according to the perception of plosives (Repp, 1984) • Perception is categorical if the peak in discrimination corresponds to the category crossover found in identification. • Experiments in the prosodic research area: • House (1996) • Kohler (1987, 1990) • Ladd & Morton (1997) • Remijsen & van Heuven (1999); van Heuven & Kirsner (2004) • Schneider & Lintfert (2003) • Falé & Hub Faria (2006)

4. Perceptual Magnet Effect (PME) • Kuhl (1991): • Phonetic perception is influenced by language experience • PME: discrimination ability differs inside a category • prototype (P) attracts its immediate neighbors – low discrimination performance • around a non–prototype (NP) – better discrimination performance

5. Experimental designs • Testing for CP and PME simultaneously • Identification: assign stimulus to one of the given categories • Goodness rating (only for PME): • separately for each category found in identification • How well does the presented stimulus fits into the assigned category? scale given • Discrimination: • Does the presented stimulus pair consists of identical or of different stimuli? • differences in the construction of stimulus pairs between CP and PME test design

6. Stimulus preparation • Test for German boundary tones (BT) • Test stimulus: • ambiguous between statement/question interpretation • no syntactic bias: PP • noun consisting of mostly sonorants; no /ə/ • pitch accent not on the last syllable • polysyllabic noun; no compound noun • “ins kalte Panama” (in the cold Panama), embedded in carrier sentences • male native German speaker

7. Stimulus preparation • Manipulation of fundamental frequency (F0) of the last 2 syllables of the target PP: • Calculation F0 range: mean rise to H%: 90 Hz; mean fall to L% : 50 Hz • ERB (Equivalent Rectangular Bandwidth) scale used • PSOLA resynthesis • Headphones used during each test

8. Additional stimuli for PME test H% H*L 0,338ERB L% Additional stimuli for PME test

9. Perception of German boundary tones (without context) • Results (25 subjects (10 females)): • s-shaped curves in identification; 2 categories • CP and PME for the statement category: • clear prototype & non-prototype (goodness rating) • disc. peak & warping of perceptual space around P • unclear results for the question category: • better within-category discrimination performance than in statement category → no clear CP, but also no gradual perception • individual prototypes differ → no PME • problematic: combination of CP and PME test design in discrimination

10. Perceptual reference space

11. Perception of German boundary tones (including context information) • Why? • context might have an influence on the location of the category boundary • there is always context in normal conversation – no “out-of-the-blue” sentences • How? • 2 different context types we tested for: • BT height of the preceding sentence (influence of F0)) • syntactic structure of the preceding sentence (influence of syntax) • same speaker as in previous experiment

12. Contexts: fundamental frequency (F0) • Does the F0 of the preceding sentence influences perception? • preceding sentences: statement vs. question; only difference in BT height a) “Er will verreisen. Nach Panama./?” b) “Er will verreisen? Nach Panama./?” H% L% condition L% L% H% H% H% condition L%

13. Contexts: syntax • Does the syntactic structure of the preceding sentence influences perception? • preceding sentences: synt. statement vs. synt. question; differ in their syntactical constructions a) “Er will verreisen. Nach Panama./?” c) “Was liegt da? Ein Ticket nach Panama./?” H% L% condition L% L% H% Wh_L% condition L% L%

14. Identification • 20 stimuli in each condition; 10 repetitions = 600 stimuli; randomized order • 3 subtests: each incl. 6 training stimuli & 200 test stimuli • 36 participants (23 females, 13 males) • Exclusion of high reaction times (RT): • outliers > 2*sdev+mean • RT outliers > 2,374614 • 2,5% of the data excluded

15. Identification: general results • Results: • clear s-shaped curves for all contexts L% H% Wh_L%

16. Identification: general results • Results: • clear s-shaped curves for all contexts • significant differences • inside the BT-height condition • as well as inside the syntax condition • there seems to be an influence on the location of the category boundary in each context condition in the intended direction

17. Identification: gender differences • Gender differences: • in each single context condition as well as pooled over all data, females: • show an earlier crossover than males condition Wh_L% condition L% condition H% pooled over all contexts

18. Identification: gender differences • Gender differences: • in each single context condition as well as pooled over all data, females: • show an earlier crossover than males • are significantly faster than males pooled over all contexts condition L% condition Wh_L% condition H%

19. Identification: gender differences • Gender differences: • in each single context condition as well as pooled over all data, females: • show an earlier crossover than males • are significantly faster than males • no sign. differences inside each category (‘statement’ vs. ‘question’)

20. Identification: gender differences • Differences in context conditions: • males: • only BT height influences location of category boundary L% H% L% Wh_L%

21. Identification: gender differences • Differences in context conditions: • females: • only syntax influences location of category boundary L% H% L% Wh_L%

22. Identification: RT • RT as indicator for category boundary? • males: nearly perfect match in all contexts H% condition L% condition Wh_L% condition

23. Identification • RT as indicator for category boundary? • females: nearly perfect match (except H% condition) Wh_L% condition L% condition H% condition

24. Summary Identification • significant gender differences with respect to the • category boundary location • reaction times • significant differences between presented context conditions, however • gender of the participant has to be taken into account

25. Outlook • finish the analyses of this experiment: • Goodness rating & CP discrimination: on the poster • PME discrimination analysis: currently running • Perceptual reference maps & comparison to without- context results • further experiments: • Finish experiment with female voice & compare possible gender-specific behavior to male-voice experiments • Experiments concerning pitch accents (preparation finished) & analyze the results

26. Thank you! Questions? Comments? Suggestions? …