1. Funded by NIH grant RO1 HD-4152 to J. Arnold NSF BCS-0318456 and NSF BCS-0318456 to Z. Griffin Why do speakers modulate acoustic prominence? Listener-oriented explanation: Acoustic prominence (duration, pitch movement, high pitch, intensity) communicates something to the listener the referent is discourse-new / not-salient (Brown, 1983) contrast (Terken & Hirschberg, 1994) informativeness (Bolinger, 1986) accent signals the focus structure (Selkirk, 1996) provides additional information in the case of low predictability words duration shorter when predictable (Jurafsky et al., 2001; Gahl & Garnsey 2004) words less intelligible when predictable (Fowler & Housum, 1987, Bard & Aylett, 2004) Speaker-internal effort also increases acoustic prominence: Speaker disfluency correlates with characteristics of acoustic prominence longer duration (Bell et al., 2003) higher pitch (Christodoulou & Arnold, Prosody08 poster) Bard & Aylett (2004): intelligibility loss for repeated words occurs even with a new addressee Higher pitch, longer duration, more pauses for unpredictable game moves (Watson, Arnold, & Tanenhaus, 2008) Research Question Does nonlinguistic, task-unrelated effort also increase acoustic prominence? Test case: Memory Load Story-telling experiment 1.Subject sees panel 1 and hears sentence 2.Subject sees panel 2, repeats sentence 1 and adds a line to the story Concurrent Digit load How acoustically prominent is the reference to the main character? The main character (Here Mickey) is larger / more interesting  start of response Only names included (pronouns excluded) Only two-character conditions included (“single char” condition yielded pronouns) Results: Longer Duration Under Memory Load Multilevel model (SAS proc mixed) of log duration: significant effects: not significant effects in model ( = marginal): load (0, 2, or 3 digits) p <.02)condition target word (p <.05)digit span utterance length (p <.05)number digits remembered continuation (p <.05)disfluency control variables (List, load order, block, list order) Load also decreased frequency of pronoun use Mickey first: Mickey did some tricks with Daisy at the Western theme park. OR Mickey second: Daisy did some tricks with Mickey at the Western theme park. Mickey did some tricks with Daisy at the Western theme park..... Mickey was good with the rope. References Babwah, L. (2008). Distraction and Reference in Discourse. Honors Thesis, UNC Chapel Hill. Bard, E. G., & Aylett, M. P. (2004). Referential form, word duration, and modeling the listener in spoken dialogue. In J. C. Trueswell & M. K. Tanenhaus (Eds.), Approaches to studying world- situated language use: Bridging the language-as-product and language-as-action traditions (pp. 173-191). Cambridge, MA: MIT Press. Bell, A., Jurafsky, D., et al.. (2003). Effects of disfluencies, predictability, and utterance position on word form variation in English conversation. JASA, 113(2), 1001-1024. Bolinger, D. (1986). Intonation and its parts melody in spoken English. Stanford, CA: Stanford University Press. Brown, G. (1983). Prosodic structure and the given/new distinction. In A. Cutler & D. R. Ladd (Eds.), Prosody, models, and measurements. New York: Springer-Verlag. Christodoulou, A., & Arnold, J. E. (2008). Effects of production difficulty on prosody. Poster; Prosody08. Fowler, C. A., & Housum, J. (1987). Talkers’ signaling of ‘‘new’’ and ‘‘old’’ words in speech and listeners’ perception and use of the distinction. JML, 26, 489–504. Gahl, S. & Garnsey, S. M. (2004). Knowledge of grammar, knowledge of usage: Syntactic probabilities affect pronunciation variation. Language, 80, 748-775 Jurafsky, D., Bell, A., Gregory, M., & Raymond, W. (2001). Probabilistic relations between words... In J. Bybee & P. Hopper (Eds.), Frequency and the emergence of linguistic structure (pp. 229- 254). Amsterdam: John Benjamins. Selkirk, E. O. (1996). Sentence prosody: Intonation, stress and phrasing. In J. A. Goldsmith (Ed.), The handbook of phonological theory (pp. 550–569). Cambridge, Mass, USA: Blackwell. Terken, J., & Hirschberg, J. (1994). Deaccentuation of words representing ‘given’ information…. Language and Speech, 37, 125-145. Watson, D., Arnold, J.E., & Tanenhaus, M. K. (2008). Tic tac TOE: Effects of predictability and importance on acoustic prominence in language production. Cognition, 106, 1548-1557. Conclusions Nonlinguistic task demands increase acoustic prominence Memory task: effort affects duration Distraction task: effort affects pitch Production-internal load decreases both acoustic and lexical attenuation The semantic/ pragmatic functions of acoustic prominence may partly reflect associated speaker-internal cognitive demands No load 2 5 3 9 6 Converging Evidence: Babwah (2008) Instructions to given or new entities Secondary, nonlinguistic task (responding to beeps) can distract speaker Distraction also decreased pronoun use Click on the cow. (beep! beep!) Now move the carrot to the circle. Cognitive Effort Influences Acoustic Prominence: The Impact of Memory Resources Jennifer E. Arnold and Zenzi M. Griffin UNC Chapel Hill Georgia Tech