Contrastive Alveolar/Retroflex Phonemes in Singapore Mandarin Bilinguals: Comprehension Rates for Articulations in Different Accents, and Acoustic Analysis of Productions.

The standard Beijing variety of Mandarin has a clear alveolar-retroflex contrast for phonemes featuring voiceless sibilant frication (i.e., /s/, /ʂ/, /ʈs/, /ʈʂ/, /ʈsʰ/, /ʈʂʰ/). However, some studies show that varieties in the 'outer circle', such in Taiwan, have a reduced contrast for these speech sounds via a process known as 'deretroflexion'. The variety of Mandarin spoken in Singapore is also considered as 'outer circle', as it exhibits influences from Min Nan varieties. We investigated how bilinguals of Singapore Mandarin and English perceive and produce speech tokens in minimal pairs differing only in the alveolar/retroflex place of articulation. In all, 50 participants took part in two tasks. In Task 1, participants performed a lexical identification task for minimal pairs differing only the alveolar/retroflex place of articulation, as spoken by native speakers of two varieties: Beijing Mandarin and Singapore Mandarin. No difference in comprehension of the words was observed between the two varieties indicating that both varieties contain sufficient acoustic information for discrimination. In Task 2, participants read aloud from the list of minimal pairs while their voices were recorded. Acoustic analysis revealed that the phonemes do indeed differ acoustically in terms of center of gravity of the frication and in an alternative measure: long-term averaged spectra. The magnitude of this difference appears to be smaller than previously reported differences for the Beijing variety. These findings show that although some deretroflexion is evident in the speech of bilinguals of the Singaporean variety of Mandarin, it does not translate to ambiguity in the speech signal.

Creating a Corpus of Multilingual Parent-Child Speech Remotely: Lessons Learned in a Large-Scale Onscreen Picturebook Sharing Task.

With lockdowns and social distancing measures in place, research teams looking to collect naturalistic parent-child speech interactions have to develop alternatives to in-lab recordings and observational studies with long-stretch recordings. We designed a novel micro-longitudinal study, the Talk Together Study, which allowed us to create a rich corpus of parent-child speech interactions in a fully online environment (N participants = 142, N recordings = 410). In this paper, we discuss the methods we used, and the lessons learned during adapting and running the study. These lessons learned cover nine domains of research design, monitoring and feedback: Recruitment strategies, Surveys and Questionnaires, Video-call scheduling, Speech elicitation tools, Videocall protocols, Participant remuneration strategies, Project monitoring, Participant retention, and Data Quality, and may be used as a primer for teams planning to conduct remote studies in the future.