Coarticulation with alveopalatal sibilants in Mandarin and Polish: Phonetics or phonology?

Previous work has shown that vowels following alveopalatal sibilants typically exhibit raised second formant (F2) values, typically attributed to coarticulatory vowel fronting (e.g. Stevens, 2004 in Mandarin; Bukmaier & Harrington, 2016 in Polish). This paper re-examines the palatalizing coarticulatory effects of the alveopalatal sibilant in Mandarin and Polish. While previous studies have focused on differences in F2 transitions or values at vowel onset, I find that the raised F2 values following alveopalatal sibilants frequently persist through the entire duration of following vowels in Mandarin. This raises the question of whether this is a phonetic coarticulation effect or a phonological assimilation effect. I review diagnostics for such a distinction and provide evidence from speech rate which suggests that the raised F2 effect should be analyzed as phonological assimilation in Mandarin, but phonetic coarticulation in Polish. These results have implications for phonological representations and perception in both languages

Cross-language Differences in Fricative Processing and Their Influence on Non-native Fricative Categorisation

Studies have shown that native speakers of Mandarin Chinese and Hong Kong Cantonese tend to have difficulty perceiving the English fricative /θ/. However, although both languages have /f/ and /s/ categories, Mandarin speakers tend to assimilate it to their /s/ category whilst Cantonese speakers would assimilate it to their /f/ category. Over three studies, this thesis investigated various factors that may lead to this difference, while enhancing our understanding of the acoustics and the perception of the fricatives of these languages. Study 1 explored acoustic properties of target fricatives of the three languages (Mandarin, Cantonese, English) using audio recordings from native speakers, and conducted comparisons of the fricatives within and across languages. The results showed that the phonemes /f s/, even though shared by the three languages, were produced differently in the different languages, likely due to the effects of the different fricative inventories. Moreover, different acoustic cues were more or less effective in distinguishing between the different fricatives in each language, indicating that native speakers of these languages likely rely on these cues differently. Study 2 examined how transition cues may affect the identification of /f/ and /s/ by native speakers of the respective languages by combining a phoneme monitoring task and EEG measures. Target fricatives were spliced with vowels to create stimuli with congruent or incongruent transitions. In contrast to previous studies (e.g., Wagner, Ernestus & Cutler, 2006), the results revealed that all groups attended to formant transitions when processing fricatives, despite their differing native fricative inventory sizes. Study 3 investigated cross-language differences in categorisation boundaries of target fricative pairs using a behavioural identification task. The study interpolated pairs of stimuli to create a frication continuum and a vowel continuum, forming a 2-dimensional stimuli grid. The results indicated that frication was the primary cue for fricative identification for the native English, Cantonese, and Mandarin speakers, but also revealed cross-language differences in fricative boundaries. Overall, the results of these studies demonstrate that the processing of fricatives was largely driven by the frication section, and the differential assimilation of /θ/ was likely due to the different acoustics of the same fricative category across languages. The results also motivate a reconsideration of the role of coarticulatory cues in fricative perception

Formant transitions in fricative identification: The role of native fricative inventory

The distribution of energy across the noise spectrum provides the primary cues for the identification of a fricative. Formant transitions have been reported to play a role in identification of some fricatives, but the combined results so far are conflicting. We report five experiments testing the hypothesis that listeners differ in their use of formant transitions as a function of the presence of spectrally similar fricatives in their native language. Dutch, English, German, Polish, and Spanish native listeners performed phoneme monitoring experiments with pseudowords containing either coherent or misleading formant transitions for the fricatives / s / and / f /. Listeners of German and Dutch, both languages without spectrally similar fricatives, were not affected by the misleading formant transitions. Listeners of the remaining languages were misled by incorrect formant transitions. In an untimed labeling experiment both Dutch and Spanish listeners provided goodness ratings that revealed sensitivity to the acoustic manipulation. We conclude that all listeners may be sensitive to mismatching information at a low auditory level, but that they do not necessarily take full advantage of all available systematic acoustic variation when identifying phonemes. Formant transitions may be most useful for listeners of languages with spectrally similar fricatives

The articulatory and acoustic characteristics of Polish sibilants and their consequences for diachronic change

The study is concerned with the relative synchronic stability of three contrastive sibilant fricatives /s (sic)/ in Polish. Tongue movement data were collected from nine first-language Polish speakers producing symmetrical real and non-word CVCV sequences in three vowel contexts. A Gaussian model was used to classify the sibilants from spectral information in the noise and from formant frequencies at vowel onset. The physiological analysis showed an almost complete separation between /s (sic)/ on tongue-tip parameters. The acoustic analysis showed that the greater energy at higher frequencies distinguished /s/ in the fricative noise from the other two sibilant categories. The most salient information at vowel onset was for /(sic)/, which also had a strong palatalizing effect on the following vowel. Whereas either the noise or vowel onset was largely sufficient for the identification of /s (sic)/ respectively, both sets of cues were necessary to separate /(sic)/ from /s (sic)/. The greater synchronic instability of /(sic)/ may derive from its high articulatory complexity coupled with its comparatively low acoustic salience. The data also suggest that the relatively late stage of /(sic)/ acquisition by children may come about because of the weak acoustic information in the vowel for its distinction from /s/

Perceptual distinctiveness between dental and palatal sibilants in different vowel contexts and its implications for phonological contrasts

Mandarin Chinese has dental, palatal, and retroflex sibilants, but their contrasts before [_i] are avoided: The palatals appear before [i] while the dentals and retroflexes appear before homorganic syllabic approximants (a.k.a. apical vowels). An enhancement view regards the apical vowels as a way to avoid the weak contrast /si-ɕi-ȿi/. We focus on the dental vs. palatal contrast in this study and test the enhancement-based hypothesis that the dental and palatal sibilants are perceptually less distinct in the [_i] context than in other vowel contexts. This hypothesis is supported by a typological survey of 155 Chinese dialects, which showed that contrastive [si, tsi, tsʰi] and [ɕi, tɕi, tɕʰi] tend to be avoided even when there are no retroflexes in the sound system. We also conducted a speeded-AX discrimination experiment with 20 English listeners and 10 Chinese listeners to examine the effect of vowels ([_i], [_a], [_ou]) on the perceived distinctiveness of sibilant contrasts ([s-ɕ], [ts-tɕ], [tsʰ-tɕʰ]). The results showed that the [_i] context introduced a longer response time, thus reduced distinctiveness, than other vowels, confirming our hypothesis. Moreover, the general lack of difference between the two groups of listeners indicates that the vowel effect is language-independent

The Development of Perceptual Sensitivity to Polish Sibilants at First Exposure

The current study examines the development of non-native phoneme discrimination in the very first hours of exposure to a second language. Thirty-six native speakers of French received a total of 14 hours of oral input in Polish over a 10-day period. None of the participants had previously studied Polish or another Slavic language and the input included no explicit phonological instruction. Participants completed an AX discrimination task at three intervals: T1 (0 hours of input), T2 (4.5 hours of input) and T3 (10.5 hours of input). Stimuli consisted of pairs of CV non-words including six sibilant fricatives from the Polish phonemic inventory. Discrimination of non-native phonemes showed a main effect of Test Interval in accuracy scores, suggesting that participants' discrimination improved significantly as a function of input. Post-hoc analyses showed, however, that the difference was only significant between T1 and T3 and between T2 and T3, suggesting that 4.5 hours of input was not sufficient for participants to begin to establish new phonemic categories. Nonetheless, the current results show a significant increase in the ability of participants to discriminate non-native sounds after very limited acoustic input in the target language, shedding light on the developmental course of adult phonological acquisition

The evolution of auditory contrast

This paper reconciles the standpoint that language users do not aim at improving their sound systems with the observation that languages seem to improve their sound systems. Computer simulations of inventories of sibilants show that Optimality-Theoretic learners who optimize their perception grammars automatically introduce a so-called prototype effect, i.e. the phenomenon that the learner’s preferred auditory realization of a certain phonological category is more peripheral than the average auditory realization of this category in her language environment. In production, however, this prototype effect is counteracted by an articulatory effect that limits the auditory form to something that is not too difficult to pronounce. If the prototype effect and the articulatory effect are of a different size, the learner must end up with an auditorily different sound system from that of her language environment. The computer simulations show that, independently of the initial auditory sound system, a stable equilibrium is reached within a small number of generations. In this stable state, the dispersion of the sibilants of the language strikes an optimal balance between articulatory ease and auditory contrast. The important point is that this is derived within a model without any goal-oriented elements such as dispersion constraints

Effects of Phonological Contrast on Within-Category Phonetic Variation

This dissertation investigates an often assumed hypothesis in phonetics and phonology: that there should be relatively less within-category phonetic variation in production in languages which have relatively more phonological contrasts (Lindblom, 1986, on vowels). Although this hypothesis is intuitive, there is little existing evidence to support the claim and it is difficult to generalize outside of vowels. In this dissertation, I argue that this hypothesis is not trivially true and needs additional specification. I propose an extension of this hypothesis, Contrast-Dependent Variation, which predicts relative differences in extent of within-category variation between languages and individual speakers. Contrast-Dependent Variation can make predictions across multiple phonetic spaces as it considers individual phonetic dimensions to be the relevant units of comparison, rather than phonological inventory subsets (stops, vowels, etc.). Relative differences in extent of within-category variation are predicted by differences in cue weight, rather than differences in number of phonemes. The dissertation tests this hypothesis by examining two between-language case studies: stops in Hindi and English and sibilants in French and Polish. I also consider a within-language case study: individual differences in extent of within-category variation in Mandarin sibilants. The results here show that differences in extent of phonetic variability between languages and speakers are systematic; they are structured according to the system of phonological contrasts

The evolution of sibilants in Polish and Russian

In this paper we provide an account of the historical development of Polish and Russian sibilants. The arguments provided here are of theoretical interest because they show that (i) certain allophonic rules are driven by the need to keep contrasts perceptually distinct, (ii) (unconditioned) sound changes result from needs of perceptual distinctiveness, and (iii) perceptual distinctiveness can be extended to a dass of consonants, i.e. the sibilants. The analysis is cast within Dispersion Theory by providing phonetic and typological data supporting the perceptual distinctiveness claims we make