Hywel Stoakes researches the sounds of speech in languages spoken today. He explores where the organisation of sound systems can inform us about our shared past and present. He works with speakers of under-resourced and endangered languages of the Asia-Pacific region to document and compare speech sounds. Recent research has focussed on the intersection between coarticulation and prosody in Indigenous Australian languages of Northern Australia, leading to collaborations with speakers of Bininj Kunwok (the Kunwinjku [kʊnˈwɪɲgʊ] variety) and Yolŋu Matha (Djambarrpuyŋu, Gumatj, Warramiri). A key aim of his research is create user-focussed computer applications engineered around iterative machine learning techniques in order to provide phonetic descriptions of under-described languages. Investigating how these tools can benefit language communities, as well as helping the modern linguist rapidly document languages that are under-resourced.
Postdoctoral Fellow, 2018
The School of Engineering, The University of Auckland
PhD in Articulatory Phonetics, 2014
The School of Linguistics and Applied Linguistics, The University of Melbourne
BA(Hons) in Linguistics, 2004
The University of Melbourne
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.
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 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.