School of Languages and Linguistics - Research Publications

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    Sociophonetic Variation in Vowel Categorization of Australian English
    Loakes, D ; Clothier, J ; Hajek, J ; Fletcher, J (SAGE PUBLICATIONS LTD, 2023-10-13)
    This study involves a perceptual categorization task for Australian English, designed to investigate regional and social variation in category boundaries between close-front vowel contrasts. Data are from four locations in southeast Australia. A total of 81 listeners from two listener groups took part: (a) so-called mainstream Australian English listeners from all four locations, and (b) L1 Aboriginal English listeners from one of the locations. Listeners heard front vowels /ɪ e æ/ arranged in 7-step continua presented at random. Varied phonetic contexts were analyzed, with a focus on coda /l/ because of a well-known prelateral merger of /e æ/ through mid-vowel lowering (e.g., celery-salary) reported to occur in some communities in this part of Australia. The results indicate that regional variation in Australian English is evident in perception. In particular, merging of /el/-/æl/ is shown to occur in the southernmost regions analyzed, but rarely in the northern regions of the geographical area under investigation. Aside from regional variation observed, age was also a factor in how participants responded to the task: older speakers had more merger than younger speakers in many locations, which is a new finding-previously, the merger was thought to be increasing in frequency over time, yet here we see this in only one location. Aboriginal English listeners also responded differently when compared with mainstream Australian English listeners. By analyzing the perception results across a variety of regional locations, with data from two different Australian social groups in the same location, this study adds a new dimension to our understanding of regional and social variations in Australian English.
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    Phrase-level and edge marking in Drehu
    Torres, C ; Fletcher, J (OPEN LIBRARY OF HUMANITIES, 2022-06-07)
    This study investigates prosodic correlates of phrasing in Drehu, an Oceanic language from New Caledonia. The analysis is concerned with the demarcation of prosodic levels in the language, namely the Accentual Phrase and the Intonation Phrase. First impressionistic descriptions of Drehu state there is fixed word initial stress, however recent experimental evidence does not support this claim. Instead, it has been suggested that Drehu could be an edge-marking language which relies on right boundary marking. To determine whether the patterns recorded in the literature are borne out, the phonological and phonetic realisation of post-lexical word level prosody is investigated. An experiment was conducted to examine the extent to which fundamental frequency (F0) and duration contribute to boundary marking in Drehu. The results show that F0 cues mark the right boundary of two prosodic levels, the AP and IP, and that the strength of the boundary is related to its level in the prosodic hierarchy. Preboundary lengthening also cues IP boundaries but not AP boundaries.
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    Prosodically Conditioned Consonant Duration in Djambarrpuyŋu.
    Jepson, K ; Fletcher, J ; Stoakes, H (SAGE Publications, 2019-03-01)
    Cross-linguistically, segments typically lengthen because of proximity to prosodic events such as intonational phrase or phonological phrase boundaries, a phrasal accent, or due to lexical stress. Australian Indigenous languages have been claimed to operate somewhat differently in terms of prosodically conditioned consonant lengthening and strengthening. Consonants have been found to lengthen after a vowel bearing a phrasal pitch accent. It is further claimed that this post-tonic position is a position of prosodic strength in Australian languages. In this study, we investigate the effects of proximity to a phrasal pitch accent and prosodic constituent boundaries on the duration of stop and nasal consonants in words of varying lengths in Djambarrpuyŋu, an Australian Indigenous language spoken in northeast Arnhem Land, Northern Territory, Australia. Our results suggest that the post-tonic consonant position does not condition longer consonant duration compared with other word-medial consonants, with one exception: Intervocalic post-tonic consonants in disyllabic words are significantly longer than word-medial consonants elsewhere. Therefore, it appears that polysyllabic shortening has a strong effect on segment duration in these data. Word-initial position did not condition longer consonant duration than word-medial position. Further, initial consonants in higher-level prosodic domains had shorter consonant duration compared with domain-medial word-initial consonants. By contrast, domain-final lengthening was observed in our data, with word-final nasals preceding a pause found to be significantly longer than all other consonants. Taken together, these findings for Djambarrpuyŋu suggest that, unlike other Australian languages, post-tonic lengthening is not a cue to prosodic prominence, whereas prosodic domain-initial and -final duration patterns of consonants are like those that have been observed in other languages of the world.
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    Nafsan
    Billington, R ; Thieberger, N ; Fletcher, J (CAMBRIDGE UNIV PRESS, 2023-08)
    Nafsan (ISO 639-3: erk, Glottocode: sout2856), also known as South Efate, is a Southern Oceanic language of Vanuatu. It is spoken in Erakor, Eratap and Pango, three villages situated along the southern coast of the island of Efate (Figure 1) (Clark 1985, Lynch 2000, Thieberger 2006). Nafsan is also closely related to Eton, Lelepa, Nakanamanga and Namakura, spoken further to the north on Efate and some smaller neighbouring islands.1 Nafsan is often described as the southernmost member of the North-Central Vanuatu group of languages, and the Nafsan and Eton-speaking communities are noted to be at the core of ‘an unmistakable area of innovation’ compared to their northern neighbours (Clark 1985: 25). Though crosslinguistic comparisons suggest a clear boundary between North-Central Vanuatu languages and languages of the Southern Vanuatu group, there is evidence that Nafsan speakers have both linguistic and cultural links to the southern islands, suggestive of complex historical relationships between the populations of the central and southern regions (Lynch 2004; Thieberger 2007, 2015). In terms of the sound system, Nafsan is noted to be of particular interest because it ‘forms a transition between the phonologically more conservative languages to the north and the more “aberrant” languages to the south’ (Lynch 2000: 320), and exhibits phonotactic patterns which are complex and typologically uncommon, particularly among Oceanic languages (Thieberger 2006).
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    Nasal coarticulation in Bininj Kunwok: An aerodynamic analysis
    Stoakes, HM ; Fletcher, JM ; Butcher, AR (Cambridge University Press (CUP), 2020-12-01)
    Bininj Kunwok (BKw), a language spoken in Northern Australia, restricts the degree of anticipatory nasalization, as suggested by previous aerodynamic and acoustic analyses (Butcher 1999). The current study uses aerodynamic measurements of speech to investigate patterns of nasalization and nasal articulation in Bininj Kunwok to compare with Australian languages more generally. The role of nasal coarticulation in ensuring language compre-hensibility a key question in phonetics research today is explored. Nasal aerodynamics is measured in intervocalic, word-medial nasals in the speech of five female speakers of BKw and data are analyzed using Smoothing Spline Analysis of Variance (SSANOVA) and Functional Data Analysis averaging techniques. Results show that in a VNV sequence there is very little anticipatory vowel nasalization with no restriction on carryover nasalization for a following vowel. The maximum peak nasal flow is delayed until the oral release of a nasal for coronal articulations, indicating a delayed velum opening gesture. Patterns of anticipatory nasalization appears similar to nasal airflow in French non-nasalized vowels in oral vowel plus nasal environments (Delvaux et al. 2008). Findings show that Bininj Kunwok speakers use language specific strategies in order to limit anticipatory nasalization, enhancing place of articulation cues at a site of intonational prominence which also is also the location of the majority of place of articulation contrasts within the language. Patterns of airflow suggest enhancement and coarticulatory resistance in prosodically prominent VN and VNC sequences which we interpret as evidence of speakers maintaining a phonological contrast to enhance place of articulation cues.
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    The alignment of F0 tonal targets under changes in speech rate in Drehu
    Torres, C ; Fletcher, J (Nature Research, 2020-04-01)
    This study investigates fundamental frequency alignment to segmental landmarks in Drehu, an Oceanic language. The authors present a production experiment that aimed to evaluate the marking of prosodic prominence, and in particular, the tonal marking of prominence, within the autosegmental-metrical phonology, since stress and prominence system of the language has not been phonetically investigated. A rate manipulation paradigm was chosen to test the segmental anchoring hypothesis, namely, to see whether prominence lending tonal movements exhibit a constant slope due to rate manipulation and whether tonal targets can be associated to segmental anchoring points in the speech stream. The authors find that a rising tonal movement, between a word initial low (L), and a word final high (H) tone, is the most frequent tonal pattern. The word initial L tone seeks to align with the left edge whereas the H tone, at the right edge, seeks to anchor to the last full syllable. In fast speech, tonal targets are produced closer together but the slope remains constant in both speech rates. High tones seek to anchor to the word-final syllable, yet not to any specific segment which suggests a weak version of the segmental anchoring hypothesis applies.
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    Fundamental Frequency and Regional Variation in Lifou French
    Torres, C ; Fletcher, J ; Wigglesworth, G (SAGE PUBLICATIONS LTD, 2022-12)
    This study presents two experiments aimed at investigating tune-to-text alignment and pitch scaling in Lifou French, a variety spoken by bilingual speakers of French and Drehu. Descriptions of New Caledonian French have focussed on language use of European descendants or the variety spoken in the urban region, neglecting emergent varieties spoken by the indigenous population in rural areas, like the island Lifou. Due to the reduced inventory of pitch accents, dialectal variation in French intonation has proved to be difficult to detect, which has led to the assumption that French has a relatively homogeneous intonation system across its varieties. This study shows that fine-grained phonetic differences in speaking tempo and at the level of tonal alignment as well as in the scaling of AP-final peaks can be attributed to dialectal variation.
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    Phonetic evidence for phonotactic change in Nafsan (South Efate)
    Billington, R ; Thieberger, N ; Fletcher, J (Pacini Editore SpA, 2020)
    Nafsan, an Oceanic language of central Vanuatu, is notable for the complex phonotactic structures it exhibits compared to languages spoken further to the north, and compared to the general preference for CV syllables among Oceanic languages. Various types of heterorganic consonant clusters are found in syllable onsets, and are thought to have arisen from the loss of selected medial vowels. Medial vowel deletion is suggested to be a process of change which has been underway for some time in the language, but the details of how this process operates have not been fully clear. Unresolved questions relating to the status of length in the vowel system and the location of lexical prominence have posed a challenge to arriving at a detailed description of vowel deletion and its consequences. Drawing together recent phonetic analyses and previous work, this paper provides an overview of phonotactic structures in contemporary Nafsan and outlines the main factors which lead to the deletion of medial vowels and result in the complex syllable onsets observed today.
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    Acoustic evidence for right-edge prominence in Nafsan
    Billington, R ; Fletcher, J ; Thieberger, N ; Volchok, B (AIP Publishing LLC, 2020)
    Oceanic languages are often described as preferring primary stress on penultimate syllables, but detailed surveys show that many different types of prominence patterns have been reported across and within Oceanic language families. In some cases, these interact with segmental and phonotactic factors, such as syllable weight. The range of Oceanic prominence patterns is exemplified across Vanuatu, a linguistically diverse archipelago with over 130 languages. However, both impressionistic and instrumentally-based descriptions of prosodic patterns and their correlates are limited for languages of this region. This paper investigates prominence in Nafsan, an Oceanic language of Vanuatu for which previous observations of prominence differ. Acoustic and durational results for disyllabic and trisyllabic Nafsan words show a clear pattern of higher fundamental frequency values in final syllables, regardless of vowel length, pointing towards a preference for prominence at the right edge of words. Short vowels also show centralisation in penultimate syllables, providing supporting evidence for right-edge prominence and informing the understanding of vowel deletion processes in Nafsan.
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    Acoustic analysis of the effects of sustained wakefulness on speech
    Vogel, AP ; Fletcher, J ; Maruff, P (ACOUSTICAL SOC AMER AMER INST PHYSICS, 2010-12)
    Exposing healthy adults to extended periods of wakefulness is known to induce changes in psychomotor functioning [Maruff et al. (2005). J. Sleep Res. 14, 21-27]. The effect of fatigue on speech is less well understood. To date, no studies have examined the pitch and timing of neurologically healthy individuals over 24 h of sustained wakefulness. Therefore, speech samples were systematically acquired (e.g., every 4 h) from 18 healthy adults over 24 h. Stimuli included automated and extemporaneous speech tasks, sustained vowel, and a read passage. Measures of timing, frequency and spectral energy were derived acoustically using PRAAT and significant changes were observed on all tasks. The effect of fatigue on speech was found to be strongest just before dawn (after 22 h). Specifically, total speech time, mean pause length, and total signal time all increased as a function of increasing levels of fatigue on the reading tasks; percentage pause and mean pause length decreased on the counting task; F4 variation decreased on the sustained vowel tasks /a:/; and alpha ratio increased on the extemporaneous speech tasks. These findings suggest that acoustic methodologies provide objective data on central nervous system functioning and that changes in speech production occur in healthy adults after just 24 h of sustained wakefulness.