No abstract

A prerequisite for spoken language learning is segmenting continuous speech into words. Amongst many possible cues to identify word boundaries, listeners can use both transitional probabilities between syllables and various prosodic cues. However, the relative importance of these cues remains unclear, and previous experiments have not directly compared the effects of contrasting multiple prosodic cues. We used artificial language learning experiments, where native German speaking participants extracted meaningless trisyllabic “words” from a continuous speech stream, to evaluate these factors. We compared a baseline condition (statistical cues only) to five test conditions, in which word-final syllables were either (a) followed by a pause, (b) lengthened, (c) shortened, (d) changed to a lower pitch, or (e) changed to a higher pitch. To evaluate robustness and generality we used three tasks varying in difficulty. Overall, pauses and final lengthening were perceived as converging with the statistical cues and facilitated speech segmentation, with pauses helping most. Final-syllable shortening hindered baseline speech segmentation, indicating that when cues conflict, prosodic cues can override statistical cues. Surprisingly, pitch cues had little effect, suggesting that duration may be more relevant for speech segmentation than pitch in our study context. We discuss our findings with regard to the contribution to speech segmentation of language-universal boundary cues vs. language-specific stress patterns.

This paper accounts for stress-pattern diversity in languages such as English, where words that are otherwise equivalent in terms of phonotactic structure and morphosyntactic category can take both initial and final stress, as seen in ˈlentil–hoˈtel, ˈenvoy–deˈgree, ˈresearchN–reˈsearchNand ˈaccessV–acˈcessV. Addressing the problem in general and abstract terms, we identify systematic conditions under which stress-pattern diversity becomes stable. We hypothesise that words adopt stress patterns that produce, on average, the best possible phrase-level rhythm. We model this hypothesis in evolutionary game theory, predict that stress-pattern diversity among polysyllabic word forms depends on the frequency of monosyllables and demonstrate how that prediction is met both in Present-Day English and in its history.

This book takes an exciting perspective on language change, by explaining it in terms of Darwin's evolutionary theory. Looking at a number of developments in the history of sounds and words, Nikolaus Ritt shows how the constituents of language can be regarded as mental patterns, or 'memes', which copy themselves from one brain to another when communication and language acquisition take place. Memes are both stable in that they transmit faithfully from brain to brain, and active in that their success at replicating depends upon their own properties. Ritt uses this controversial approach to challenge established models of linguistic competence, in which speakers acquire, use, and shape language. In Darwinian terms, language evolution is something that happens to, rather than through, speakers, and the interests of linguistic constituents matter more than those of their human 'hosts'. This book will stimulate debate among evolutionary biologists, cognitive scientists and linguists alike.

When speaking a foreign language, non-native speakers can typically be readily identified by their accents. But which aspects of the speech signal determine such accents? Speech pauses occur in all languages but may nonetheless vary in different languages with regard to their duration, number or positions in the speech stream, and therefore are one potential contributor to foreign speech production. The aim of this study was therefore to investigate whether non-native speakers pause 'with a foreign accent'. We recorded native English speakers and non-native speakers of German or Serbo-Croatian with excellent English reading out an English text at three different speech rates, and analyzed their vocal output in terms of number, duration and location of pauses. Overall, all non-native speakers were identified by native raters as having non-native accents, but native and non-native speakers made pauses that were similarly long, and had similar ratios of pause time compared to total speaking time. Furthermore, all speakers changed their pausing behavior similarly at different speech rates. The only clear difference between native and non-native speakers was that the latter made more pauses than the native speakers. Thus, overall, pause patterns contributed little to the acoustic characteristics of speakers' non-native accents, when reading aloud. Non-native pause patterns might be acquired more easily than other aspects of pronunciation because pauses are perceptually salient and producing pauses is easy. Alternatively, general cognitive processing mechanisms such as attention, planning or memory may constrain pausing behavior, allowing speakers to transfer their native pause patterns to a second language without significant deviation. We conclude that pauses make a relatively minor contribution to the acoustic characteristics of non-native accents.