Transition Probabilities and Different Levels of Prominence in Segmentation

Abstract

A large body of empirical research demonstrates that people exploit a wide variety of cues for the segmentation of continuous speech in artificial languages, including rhythmic properties, phrase boundary cues, and statistical regularities. However, less is known regarding how the different cues interact. In this study we addressed the question of the relative importance of lexical stress, phrasal prominence, and transitional probabilities (TP) between adjacent syllables for the segmentation of an artificial language. We explored how duration increase, pitch rise, and the combination of duration and pitch on the antepenultimate, the penultimate, and the final syllable of a three-syllabic word affect segmentation by native speakers of Italian. Our results indicate that, if the most frequent location of stress in the participants' native language and a lengthened syllable in the artificial language do not coincide, segmentation is disrupted. If there is no conflict between the location of stress in the native language of the participant and the lengthened syllable in the artificial language, segmentation is neither impeded nor facilitated. Pitch marked the edges of the TP-defined words in a continuous speech stream. When TPs and pitch cues are in conflict, segmentation fails; if pitch rise coincides with the edges of TP words, segmentation succeeds, but is not facilitated. Phrasal prominence comprising both pitch and duration facilitates segmentation when aligned with the word edges. Our findings show that language-specific peculiarities of how nuclear pitch accents are realized in the native language of the listener might interact with statistical cues in the segmentation of an unfamiliar language.

Cross-linguistic differences in the use of durational cues for the segmentation of a novel language

“…A whole body of studies have shown that although the most powerful and informative cues are not available to people segmenting speech in a novel language, they can nevertheless successfully cope with segmentation tasks (Wakefield, Doughtie, & Yom, 1974;Pilon, 1981). In the absence of higher-level linguistic information, listeners rely on other cues, including segmental (phonotactic, allophonic) and prosodic (duration, intensity, pitch) cues, which signal lexical stress, as well as other levels of prominence, and phrase boundaries (Vroomen, Tuomainen, & de Gelder, 1998;Toro, Pons, Bion, & Sebastián-Gallés, 2011;Langus, Marchetto, Bion, & Nespor, 2012;Ordin & Nespor, 2013). Differences in transitional probabilities (TPs) between adjacent syllables within words or straddling the word boundaries are also used to segment words from an artificial language (Saffran, Newport, & Aslin, 1996), as well as frequency distribution of moreand less frequent speech constituents (de la Cruz-Pavia, Elordieta, Sebastián-Gallés, & Laka, 2014;Gervain, Sebastian-Galles, Diaz, Laka, Mazuka, Yamane, Nespor, & Mehler, 2013).…”

“…Finally, it is worth taking into account that although the presence of final lengthening has been attested cross-linguistically, its phonetic implementation 5 and the domain over which final lengthening operates is language-specific (Nakai et al, 2012 for Finnish;White & Turk, 2010;Turk & Shattuck-Hufnagel, 2007;Whightman et al, 1992 for English;CambierLangeveld, Nespor, & van Heuven, 1997 for Dutch;Frota, 2000 for Portuguese;Elodrieta, Frota, & Vigário, 2005 for Spanish and Portuguese; D'Imperio, Elordieta, Frota, Prieto & Vigário, 2005 for other Romance languages). Such cross-linguistic differences in the functional load and acoustic manifestation of lengthening cues lead some researchers to suggest that lengthening cues for the segmentation of an unknown language might be language-specific and, at least to some extent, depend on the first language (L1) of the listener (Ordin & Nespor, 2013;Ordin & Nespor, 2016;de la Mora, Nespor, Toro, 2013;Toro & Nespor, 2015;Bhatara, BollAvetisyan, Unger, Nazzi & Hoehle, 2013). Ordin and Nespor (2013; showed that Germans indeed use lengthening as the phrase boundary marker, and when the lengthened syllable in a novel language marked the right edge of the discrete constituent, the segmentation performance improves.…”

“…Such cross-linguistic differences in the functional load and acoustic manifestation of lengthening cues lead some researchers to suggest that lengthening cues for the segmentation of an unknown language might be language-specific and, at least to some extent, depend on the first language (L1) of the listener (Ordin & Nespor, 2013;Ordin & Nespor, 2016;de la Mora, Nespor, Toro, 2013;Toro & Nespor, 2015;Bhatara, BollAvetisyan, Unger, Nazzi & Hoehle, 2013). Ordin and Nespor (2013; showed that Germans indeed use lengthening as the phrase boundary marker, and when the lengthened syllable in a novel language marked the right edge of the discrete constituent, the segmentation performance improves. However, Italians do not conform to this general pattern.…”

“…Therefore, it is not yet clearly answered whether lengthening in a novel language is processed universally by speakers with different native languages, as suggested by Tyler and Cutler (2009) or Kim et al (2012), or whether it is coherent with the linguistic input, as suggested by Ordin and Nespor (2013;), Toro et al (2015 or Bhatara (2013). Considering inconsistent results reported in the literature regarding the use of lengthening for segmentation, we decided to test and refine the hypothesis of L1-specific use of lengthening cues with a larger pool of languages that exhibit more variety in the role lengthening plays in the manifestation of linguistic structure (see table 1).…”

“…Secondly, we can compare the performance of Italian and German participants who receive intentional instructions in the current study with the performance reported in Ordin and Nespor (2013;, where the listeners received incidental instructions. This will provide insight about the influence of different instructions given to the participants, and a deeper understanding of how prosodic features interact with statistical cues in word segmentation.…”