Irina A. Shport

Word-level prosody in Balsas Nahuatl: The origin, development, and acoustic correlates of tone in a stress accent language

Abstract Here we investigate the historical origins and acoustic correlates of a hypothesized tonal development in subdialects of the Nahuatl spoken in the Balsas River valley of central Guerrero state in Mexico. We hypothesize that some subdialects have developed high tone on a syllable preceding a syllable with a breathy-voiced coda [ɦ] (

Perception of acoustic cues to Tokyo Japanese pitch-accent contrasts in native Japanese and naive English listeners.

This study examines how native language shapes the perception of a prosodic contrast. In Tokyo Japanese, a high-low pitch accent is a lexical property of a word, and the F0 fall after the peak associated with the accented syllable is the fundamental cue to accent perception. In English, pitch accents do not create lexically contrastive F0 patterns. A hypothesis that English listeners naive to Japanese use the F0 fall cue less than Japanese listeners was tested in two experiments. The alignment of F0 peak, the presence and magnitude of F0 fall were manipulated in a trisyllabic nonword to resynthesize Japanese 1st-syllable accented, 2nd-syllable accented, and unaccented patterns. In an AX-discrimination experiment, both listener groups showed sensitivity to the presence of F0 fall at every peak location. In a categorization experiment, the English group did not use the F0 fall cue in decisions about whether the 1st or the 2nd syllable sounded more prominent. The Japanese group relied on the F0 fall information, some listeners much heavily than others. These findings suggest that ones native language constrains how much attention the prosodic dimension of F0 change receives and that individual listeners may have qualitatively different perceptual strategies.

Lexical and Phrasal Prominence Patterns in School-Aged Children's Speech

This study investigated the integration of word- and phrase-level prominences in speech produced by twenty-five school-aged children (6;2 to 7;3) and twenty-five adults. Participants produced disyllabic number words in a straight count condition and in two phrasal conditions, namely, a stress clash and non-clash phrasal context. Duration and amplitude measures of syllable rhymes were used to assess the realization of lexical stress, and fundamental frequency (F0) measures were used to assess the realization of phrasal pitch accents across conditions. Results showed that the duration and F0 correlates varied independently of each other as a function of condition in child speech, but much less so in adult speech. The group differences were taken to indicate that six-year-old children have yet to develop prosodic structures with integrated prominence. Structural and pragmatic interpretations of the results are discussed.

The effect of oral proficiency on production of rhythm in spontaneous second language (L2) Japanese speech.

This study addresses the question of whether oral proficiency in Japanese second language (L2) speech has a unique correlation with acoustic characteristics of rhythm production that is independent from segments. Among four rhythm measures used (V%, VarcoV, VarcoC, VI‐M), only two measures were different for the spontaneous L2 Japanese speech of beginning and intermediate learners. The interlanguage rhythm of less proficient speakers of Japanese was characterized by lower variability in duration of vocalic stretches (VarcoV) and higher variability in duration of consonantal stretches (VarcoC), p < 0.05. For both VarcoV and VarcoC values, the distribution of the individual speakers’ rhythm scores was much tighter and on target for the intermediate students than for the beginning students. Furthermore, VarcoV values were significantly correlated with number of utterance‐final vowels, and VarcoC values were correlated with number of obstruent clusters. In sum, the findings suggest that rhythmic differences i...

Comparing weights of cues with different numbers of levels.

Cue weighting is a useful methodological tool in speech perception research: it allows to access within‐group and between‐group biases in sound categorization. Examination of cue weighting may also have major implications for phonological theory. For instance, significant individual variation in reliance on cues to a phonemic contrast within a speech community challenges the traditional assumption of the language‐specific feature system. Morrison argued that logistic regression coefficients in identification tasks provide good estimates of cue weights [Studies in Second Lang. Acquisition 597–606 (2005)]. Unfortunately, coefficient estimates vary with the number of levels a cue has, which makes it impossible to directly compare weights of cues with different numbers of levels, a serious limitation. The present paper shows that, using a null hypothesis of zero cue weight and a fixed sample size, one can employ Monte Carlo techniques to estimate the effect of the number of levels on observed cue weights (reg...

Production characteristics of accent in four dialects of Nahuatl

Most descriptions of Nahuatl (Uto‐Aztecan, Mexico) describe regular penultimate accent, although production characteristics are unstudied. Recently, however, dialects from Guerrero state have been described with pitch‐accent from historical coda breathy /h/ in nonfinal position [Guion and Amith, J. Acoust. Soc. Am. 117, S2490 (2005)]. In the current study, the acoustic correlates of this new pitch‐accent, as well as penultimate accent, are investigated. Speakers (n=6) from four dialects–two with innovated pitch‐accent and two with only penultimate accent–were recorded. The production characteristics of fundamental frequency (F0), duration, and voice quality, as indexed by the difference between the first two harmonics (H1‐H2), were investigated. Innovated pitch‐accent was found to be cued solely by F0. Penultimate accent varied in its production by dialect. In dialects with only penultimate accent, production exhibited characteristics typical of stress‐accent: Accented syllables had higher F0, longer dura...

Flapping before a stressed vowel – whatever!

In English, word-internal intervocalic alveolar stops are predominantly flapped when preceding an unstressed vowel (water, charity) and optionally flapped at word boundaries preceding unstressed and stressed vowels (that is, private airplane). In this study, we show that /t/ is flapped in whatever although it has been considered word-internal and preceding a stressed vowel. The data were elicited in a sentence reading task, with four speakers of Appalachian English. The duration of /t/ and the acoustic correlates of stress were examined. A comparison of vowel duration and intensity patterns in whatever versus everwhat (both words are relative pronouns in free relative clauses in this dialect) showed that the second syllable is stressed in whatever. A comparison of /t/ durations showed no significant differences among whatever, watermelons, waterlilies, water buffalo (M = 30.5 ms). These results may be interpreted as: a) whatever is an exception to the word-internal flapping environment, or b) the word-internal flapping environment must be modified to include preceding stressed vowels at morpheme boundaries, or c) whatever consists of two phonological words and falls within the word-final flapping environment. Prosodic and syntactic analyses of free relative clauses consistent with the last interpretation are discussed.

A preliminary examination of the gender role in back-vowel fronting in Central Louisiana

In addition to the Southern Vowel Shift that involves /ɛ ɪ/ fronting, high back vowels also tend to be fronted in white Southern U.S. speech (Labov, Ash, & Boberg, 2006; Thomas, 2001). The tense /u/ is the first to shift in the back-vowel system, followed by the lax /ʊ/. Gender effect on the degree of fronting has been reported for one vowel but not the other: Male speakers lead in /u/fronting, whereas /ʊ/ fronting occurs more or less uniformly across speakers of different genders (Clopper, Pisoni, & de Jong; Fridland, 2001). This study provides a preliminary examination of the role of gender in the relative degree of back vowel fronting in young adult speakers from Central Louisiana. They were recorded producing words with target vowels in a variety of tasks: word list and passage reading, sentence creation, and informal conversation. The formant values were analyzed with a reference to other vowels in each speaker and with a reference to average values for Southern U.S. English reported in previous rese...

Flapping before a stressed vowel: The case of whatever

In English, word-internal intervocalic alveolar stops are predominantly flapped when preceding an unstressed vowel (water, charity) and optionally flapped at word boundaries preceding unstressed and stressed vowels (that is, private airplane). In this study, we show that /t/ is flapped in whatever although it is word-internal and precedes a stressed vowel. The data were elicited in a sentence reading task, with four speakers of Appalachian English. The duration of /t/ and the acoustic correlates of stress were examined. A comparison of vowel duration and amplitude patterns in whatever versus everwhat (both words are relative pronouns in free relative clauses in this dialect, N = 699) showed that the second syllable is stressed in whatever. A comparison of /t/ durations showed no significant differences among whatever, watermelons, waterlilies, water buffalo (N = 533, M = 30.1 ms). These results may be interpreted as: (a) whatever is an exception to the word-internal flapping environment, or (b) the word-i...

Word learning by naïve non-native speakers may not be predictable by cognitive test scores

The role of cognitive abilities in learning of words with two types of novel sounds—lexical tones and coronal consonants—was compared. Individual differences were expected to play a larger role in implicit learning of tones than consonants. Twenty-two English speakers took tests assessing working memory, attention, executive function, and processing speed (NIH & Northwestern University, 2006–2012, NIH Toolbox: Cognition). Then, they learned twelve Vietnamese words varying in their initial consonants [m, t, ʈ, ʐ] and tones (high level, falling, and rising). After training with feedback, the learning was assessed in a 12-word alternative identification test (N = 792). The range of accuracy scores was 11.1–80.6%, with the mean accuracy of 43.6% (SD = 18.5). The proportion of tonal errors was significantly larger than the proportion of consonantal errors [χ(1) = 174.68, p < 0.001]. Mixed-effect regression analyses showed, however, that cognitive test scores did not explain the variance in the word identificat...