Asymmetrical roles of segment and pitch accent in Japanese spoken word recognition.

This study examines the roles of segment and pitch accent in Japanese spoken word recognition. In a lexical decision task, it replicates the finding of Cutler and Otake [(1999) J. Acoust. Soc. Am. 105(3), 1877-1888] that pitch accent restricts word activation with a more comprehensive, rigorous experimental design. Furthermore, results uncover an asymmetrical role of segment and pitch accent in word recognition in Japanese: words primed by a pitch accent-matching prime are recognized more slowly and less accurately than words primed by a segment-matching prime.

Infants' developing sensitivity to native language phonotactics: A meta-analysis.

We used Bayesian modeling to aggregate experiments investigating infants' sensitivity to native language phonotactics. Our findings were based on data from 83 experiments on about 2000 infants learning 8 languages, tested using 4 different methods. Our results showed that, unlike with artificial languages, infants do exhibit sensitivity to native language phonotactic patterns in a lab setting. However, the exact developmental trajectory depends on the phonotactic pattern being tested. Before 8 months, infants tuned into non-local dependencies between vowels: specifically, vowel harmony. Between 8- and 10-months, infants demonstrated a consistent sensitivity to both local dependencies and non-local consonant dependencies. Sensitivity to non-local vowel dependencies that are not based on harmony emerged only after 10-months. These findings provide a benchmark for future experimental and computational research on the acquisition of phonotactics.

Intonational Structure Influences Perception of Contrastive Vowel Length: The Case of Phrase-Final Lengthening in Tokyo Japanese.

Recent research has proposed that listeners use prosodic information to guide their processing of phonemic contrasts. Given that prosodic organization of the speech signal systematically modulates durational patterns (e.g., accentual lengthening and phrase-final (PF) lengthening), listeners' perception of durational contrasts has been argued to be influenced by prosodic factors. For example, given that sounds are generally lengthened preceding a prosodic boundary, listeners may adjust their perception of durational cues accordingly, effectively compensating for prosodically-driven temporal patterns. In the present study we present two experiments designed to test the importance of pitch-based cues to prosodic structure for listeners' perception of contrastive vowel length (CVL) in Tokyo Japanese along these lines. We tested if, when a target sound is cued as being PF, listeners compensatorily adjust categorization of vowel duration, in accordance with PF lengthening. Both experiments were a two-alternative forced choice task in which listeners categorized a vowel duration continuum as a phonemically short or long vowel. We manipulated only pitch surrounding the target sound in a carrier phrase to cue it as intonational phrase final, or accentual phrase medial. In Experiment 1 we tested perception of an accented target word, and in Experiment 2 we tested perception of an unaccented target word. In both experiments, we found that contextual changes in pitch influenced listeners' perception of CVL, in accordance with their function as signaling intonational structure. Results therefore suggest that listeners use tonal information to compute prosodic structure and bring this to bear on their perception of durational contrasts in speech.