Sarah C. Creel

Distant Melodies: Statistical Learning of Nonadjacent Dependencies in Tone Sequences

Human listeners can keep track of statistical regularities among temporally adjacent elements in both speech and musical streams. However, for speech streams, when statistical regularities occur among nonadjacent elements, only certain types of patterns are acquired. Here, using musical tone sequences, the authors investigate nonadjacent learning. When the elements were all similar in pitch range and timbre, learners acquired moderate regularities among adjacent tones but did not acquire highly consistent regularities among nonadjacent tones. However, when elements differed in pitch range or timbre, learners acquired statistical regularities among the similar, but temporally nonadjacent, elements. Finally, with a moderate grouping cue, both adjacent and nonadjacent statistics were learned, indicating that statistical learning is governed not only by temporal adjacency but also by Gestalt principles of similarity.

How Talker Identity Relates to Language Processing

Speech carries both linguistic content – phonemes, words, sentences – and talker information, sometimes called ‘indexical information’. While talker variability materially affects language processing, it has historically been regarded as a curiosity rather than a central influence, possibly because talker variability does not fit with a conception of speech sounds as abstract categories. Despite this relegation to the periphery, a long history of research suggests that phoneme perception and talker perception are interrelated. The current review argues that speech perception itself may arise from phylogenetically earlier vocal recognition, and discusses evidence that many cues to talker identity are also cues to speech-sound identity. Rather than brushing talker differences aside, explicit examination of the role of talker variability and talker identity in language processing can illuminate our understanding of the origins of spoken language, and the nature of language representations themselves. Spoken language contains a great amount of communicative information. Speech can refer to things, but it also identifies or classifies the person speaking. This dual function links language to other types of vocal communication systems, and means that recognizing speech and recognizing speakers are intertwined. Imagine someone says the word cat. The vocal pitch of ‘cat’ is 200 Hz, and the delay between opening of the vocal tract and the beginning of vocal-cord vibration is 80 ms. The listener has to process all of this acoustic information to identify this word as ⁄ kaet ⁄ . Many would agree that the vocal pitch is relatively unimportant, while the 80-ms voice onset time is crucial because it distinguishes the phoneme ⁄ k ⁄ from the very similar phoneme ⁄ g ⁄ . But what happens to the ‘unimportant’ information? On a modular view, information not linked to phoneme identity is discarded by the speech-processing system (e.g. Liberman and Mattingly 1985). Nonetheless, details such as vocal pitch may influence comprehension because they indicate the speaker’s identity, and can refine the listener’s expectations about what particular speakers are likely to talk about. Differing theories of language processing have different accounts of talker identification. On one view, two separate, independent systems process speech and talker identification

Differences in Talker Recognition by Preschoolers and Adults.

Talker variability in speech influences language processing from infancy through adulthood and is inextricably embedded in the very cues that identify speech sounds. Yet little is known about developmental changes in the processing of talker information. On one account, children have not yet learned to separate speech sound variability from talker-varying cues in speech, making them more sensitive than adults to talker variation. A different account is that children are less developed than adults at recognizing speech sounds and at recognizing talkers, and development involves protracted tuning of both recognition systems. The current research presented preschoolers and adults (N=180) with voices linked to two distinct cartoon characters. After exposure, participants heard each talker and selected which character was speaking. Consistent with the protracted tuning hypothesis, children were much less accurate than adults when talkers were matched on age, gender, and dialect (Experiments 1-3), even when prosody differed (Experiment 5). Children were highly accurate when voices differed in gender (Experiment 2) or age (mother vs. daughter; Experiment 6), suggesting that greater acoustic dissimilarity facilitated encoding. Implications for speech sound processing are discussed, as are the roles of language knowledge and the nature of talker perceptual space in talker encoding.

Online Recognition of Music Is Influenced by Relative and Absolute Pitch Information.

Three experiments explored online recognition in a nonspeech domain, using a novel experimental paradigm. Adults learned to associate abstract shapes with particular melodies, and at test they identified a played melodys associated shape. To implicitly measure recognition, visual fixations to the associated shape versus a distractor shape were measured as the melody played. Degree of similarity between associated melodies was varied to assess what types of pitch information adults use in recognition. Fixation and error data suggest that adults naturally recognize music, like language, incrementally, computing matches to representations before melody offset, despite the fact that music, unlike language, provides no pressure to execute recognition rapidly. Further, adults use both absolute and relative pitch information in recognition. The implicit nature of the dependent measure should permit use with a range of populations to evaluate postulated developmental and evolutionary changes in pitch encoding.

Apples and Oranges: Developmental Discontinuities in Spoken-Language Processing?

Much research focuses on speech processing in infancy, sometimes generating the impression that speech-sound categories do not develop further. Yet other studies suggest substantial plasticity throughout mid-childhood. Differences between infant versus child and adult experimental methods currently obscure how language processing changes across childhood, calling for approaches that span development.

Impossible to _gnore: Word-Form Inconsistency Slows Preschool Children's Word-Learning

Many studies have examined language acquisition under morphosyntactic or semantic inconsistency, but few have considered word-form inconsistency. Many young learners encounter word-form inconsistency due to accent variation in their communities. The current study asked how preschoolers recognize accent-variants of newly learned words. Can preschoolers generalize recognition based on partial match to the learned form? When learning in two accents simultaneously, do children ignore inconsistent elements, or encode two word forms (one per accent)? Three- to 5-year-olds learned words in a novel-word learning paradigm but did not generalize to new accent-like pronunciations (Experiment 1) unless familiar-word recognition trials were interspersed (Experiments 3 and 4), which apparently generated a familiar-word-recognition pragmatic context. When exposure included two accent-variants per word, children were less accurate (Experiment 2) and slower to look to referents (Experiments 2, 5) relative to one-accent learning. Implications for language learning and accent processing over development are discussed.

Mandarin-English Bilinguals Process Lexical Tones in Newly Learned Words in Accordance with the Language Context

Previous research has mainly considered the impact of tone-language experience on ability to discriminate linguistic pitch, but proficient bilingual listening requires differential processing of sound variation in each language context. Here, we ask whether Mandarin-English bilinguals, for whom pitch indicates word distinctions in one language but not the other, can process pitch differently in a Mandarin context vs. an English context. Across three eye-tracked word-learning experiments, results indicated that tone-intonation bilinguals process tone in accordance with the language context. In Experiment 1, 51 Mandarin-English bilinguals and 26 English speakers without tone experience were taught Mandarin-compatible novel words with tones. Mandarin-English bilinguals out-performed English speakers, and, for bilinguals, overall accuracy was correlated with Mandarin dominance. Experiment 2 taught 24 Mandarin-English bilinguals and 25 English speakers novel words with Mandarin-like tones, but English-like phonemes and phonotactics. The Mandarin-dominance advantages observed in Experiment 1 disappeared when words were English-like. Experiment 3 contrasted Mandarin-like vs. English-like words in a within-subjects design, providing even stronger evidence that bilinguals can process tone language-specifically. Bilinguals (N = 58), regardless of language dominance, attended more to tone than English speakers without Mandarin experience (N = 28), but only when words were Mandarin-like—not when they were English-like. Mandarin-English bilinguals thus tailor tone processing to the within-word language context.

Ups and Downs in Auditory Development: Preschoolers' Sensitivity to Pitch Contour and Timbre

Much research has explored developing sound representations in language, but less work addresses developing representations of other sound patterns. This study examined preschool childrens musical representations using two different tasks: discrimination and sound-picture association. Melodic contour--a musically relevant property--and instrumental timbre, which is (arguably) less musically relevant, were tested. In Experiment 1, children failed to associate cartoon characters to melodies with maximally different pitch contours, with no advantage for melody preexposure. Experiment 2 also used different-contour melodies and found good discrimination, whereas association was at chance. Experiment 3 replicated Experiment 2, but with a large timbre change instead of a contour change. Here, discrimination and association were both excellent. Preschool-aged children may have stronger or more durable representations of timbre than contour, particularly in more difficult tasks. Reasons for weaker association of contour than timbre information are discussed, along with implications for auditory development.

Gradient phonological inconsistency affects vocabulary learning

Learners frequently experience phonologically inconsistent input, such as exposure to multiple accents. Yet, little is known about the consequences of phonological inconsistency for language learning. The current study examines vocabulary acquisition with different degrees of phonological inconsistency, ranging from no inconsistency (e.g., both talkers call a picture /vig/) to mild but detectable inconsistency (e.g., one talker calls a picture a /vig/, and the other calls it a /vIg/), up to extreme inconsistency (e.g., the same picture is both a /vig/ and a /dIdʒ/). Previous studies suggest that learners readily extract consistent phonological patterns, given variable input. However, in Experiment 1, adults acquired phonologically inconsistent vocabularies more slowly than phonologically consistent ones. Experiment 2 examined whether word-form inconsistency alone, without phonological competition, was a source of learning difficulty. Even without phonological competition, listeners learned faster in 1 accent than in 2 accents, but they also learned faster in 2 accents (/vig/ = /vIg/) than with completely different labels (/vig/ = /dIdʒ/). Overall, results suggest that learners exposed to multiple accents may experience difficulty learning when 2 forms mismatch by more than 1 phonological feature, plus increased phonological competition due to a greater number of word forms. Implications for learning from variable input are discussed.

Speaking a tone language enhances musical pitch perception in 3–5‐year‐olds

Young children learn multiple cognitive skills concurrently (e.g., language and music). Evidence is limited as to whether and how learning in one domain affects that in another during early development. Here we assessed whether exposure to a tone language benefits musical pitch processing among 3-5-year-old children. More specifically, we compared the pitch perception of Chinese children who spoke a tone language (i.e., Mandarin) with English-speaking American children. We found that Mandarin-speaking children were more advanced at pitch processing than English-speaking children but both groups performed similarly on a control music task (timbre discrimination). The findings support the Pitch Generalization Hypothesis that tone languages drive attention to pitch in nonlinguistic contexts, and suggest that language learning benefits aspects of music perception in early development. A video abstract of this article can be viewed at: https://youtu.be/UY0kpGpPNA0.