The role of vowel hyperarticulation in clear speech to foreigners and infants

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonResearch on clear speech has shown that the type of clear speech produced can vary depending on the speaker, the listener and the medium. Although prior research has suggested that clear speech is more intelligible than conversational speech for normal-hearing listeners in noisy environments, it is not known which acoustic features of clear speech are the most responsible for enhanced intelligibility and comprehension. This thesis focused on investigating the acoustic characteristics that are produced in clear speech to foreigners and infants. Its aim was to assess the utility of these features in enhancing speech intelligibility and comprehension. The results of Experiment 1 showed that native speakers produced exaggerated vowel space in natural interactions with foreign-accented listeners compared to native-accented listeners. Results of Experiment 2 indicated that native speakers exaggerated vowel space and pitch to infants compared to clear read speech. Experiments 3 and 4 focused on speech perception and used transcription and clarity rating tasks. Experiment 3 contained speech directed at foreigners and showed that speech to foreign-accented speakers was rated clearer than speech to native-accented speakers. Experiment 4 contained speech directed at infants and showed that native speakers rated infant-directed speech as clearer than clear read speech. In the fifth and final experiment, naturally elicited clear speech towards foreign-accented interlocutors was used in speech comprehension tasks for native and non-native listeners with varying proficiency of English. It was revealed that speech with expanded vowel space improved listeners’ comprehension of speech in quiet and noise conditions. Results are discussed in terms of the Lindblom’s (1990) theory of Hyper and Hypoarticulation, an influential framework of speech production and perception.Brunel University Isambard Research Scholarshi

Re-examining Phonological and Lexical Correlates of Second Language Comprehensibility:The Role of Rater Experience

Few researchers and teachers would disagree that some linguistic aspects of second language (L2) speech are more crucial than others for successful communication. Underlying this idea is the assumption that communicative success can be broadly defined in terms of speakers’ ability to convey the intended meaning to the interlocutor, which is frequently captured through a listener-based rating of comprehensibility or ease of understanding (e.g. Derwing & Munro, 2009; Levis, 2005). Previous research has shown that communicative success – for example, as defined through comprehensible L2 speech – depends on several linguistic dimensions of L2 output, including its segmental and suprasegmental pronunciation, fluency-based characteristics, lexical and grammatical content, as well as discourse structure (e.g. Field, 2005; Hahn, 2004; Kang et al., 2010; Trofimovich & Isaacs, 2012). Our chief objective in the current study was to explore the L2 comprehensibility construct from a language assessment perspective (e.g. Isaacs & Thomson, 2013), by targeting rater experience as a possible source of variance influencing the degree to which raters use various characteristics of speech in judging L2 comprehensibility. In keeping with this objective, we asked the following question: What is the extent to which linguistic aspects of L2 speech contributing to comprehensibility ratings depend on raters’ experience

Does speech prosody matter in health communication? Evidence from native and non-native English speaking medical students in a simulated clinical interaction

The impact of the UK’s multilingual and multicultural society today can be seen in its healthcare services and have contributed towards shaping communication skills training as a core part of the UK undergraduate medical curriculum. NHS complaints statistics involving perceived staff attitudes have remained high, despite extensive communication skills training. Furthermore, foreign doctors have received a higher proportion of complaints than UK doctors. Finally, how linguistic and social factors shape the conveyance and perception of attitudes related to professionalism in medical communication remains poorly understood. The ultimate aim of this study was to ascertain if speech prosody contributes to the perception of professionalism in medical communication. Research questions on the role of speech prosody in conveying professional attitudes in medical communication, the prosodic differences between native and non-native English speaking medical students in a simulated clinical interaction, and the influence of prosodic features on listeners’ perceptions of professional attitudes were addressed. A set of acoustic parameters representing the speech prosody of native and non-native medical students in the simulated clinical setting was analysed. A perceptual experiment was then carried out to investigate the factors affecting perceived professionalism in extracts of the analysed simulated clinical interaction. The examined acoustic parameters were found to be sensitive to the English language background and the task within the simulated consultation. Interestingly, the attitudinal information associated with some of these acoustic parameters were perceived by listeners and were reflected by higher professional scale scores in the perceptual experiment, even after adjusting for the English language background. The factors of training level and consultation task also emerged to be affecting professional scale scores. Initial findings have confirmed that speech prosody plays a role in terms of contributing towards the perception of professionalism in medical communication. Incorporating how messages are delivered to patients into current models of communication skills training may have positive outcomes

Do native speakers of North American and Singapore English differentially perceive comprehensibility in second language speech?

The current study examined the extent to which native speakers of North American and Singapore English differentially perceive the comprehensibility (ease of understanding) of second language (L2) speech. Spontaneous speech samples elicited from 50 Japanese learners of English with various proficiency levels were first rated by 10 Canadian and 10 Singaporean raters for overall comprehensibility and then submitted to pronunciation, fluency, vocabulary, and grammar analyses. Whereas the raters’ comprehensibility judgements were generally influenced by phonological and temporal qualities as primary cues, and, to a lesser degree, lexical and grammatical qualities of L2 speech as secondary cues, their linguistic backgrounds did make some impact on their L2 speech assessment patterns. The Singaporean raters, who not only used various models of English but also spoke a few L2s on a daily basis in a multilingual environment, tended to assign more lenient comprehensibility scores due to their relatively high sensitivity to, in particular, lexicogrammatical information. On the other hand, the comprehensibility judgements of the Canadian raters, who used only North American English in a monolingual environment, were mainly determined by the phonological accuracy and fluency of the L2 speech

The Acoustic Features and Didactic Function of Foreigner-Directed Speech: A Scoping Review

Published online: Aug 1, 2022Purpose: This scoping review considers the acoustic features of a clear speech register directed to nonnative listeners known as foreigner-directed speech (FDS). We identify vowel hyperarticulation and low speech rate as the most representative acoustic features of FDS; other features, including wide pitch range and high intensity, are still under debate. We also discuss factors that may influence the outcomes and characteristics of FDS. We start by examining accommodation theories, outlining the reasons why FDS is likely to serve a didactic function by helping listeners acquire a second language (L2). We examine how this speech register adapts to listeners’ identities and linguistic needs, suggesting that FDS also takes listeners’ L2 proficiency into account. To confirm the didactic function of FDS, we compare it to other clear speech registers, specifically infant-directed speech and Lombard speech. Conclusions: Our review reveals that research has not yet established whether FDS succeeds as a didactic tool that supports L2 acquisition. Moreover, a complex set of factors determines specific realizations of FDS, which need further exploration. We conclude by summarizing open questions and indicating directions and recommendations for future research.This research was supported by a Doctoral Fellowship (LCF/BQ/DI19/11730045) from “La Caixa” Foundation (ID 100010434) awarded to Giorgio Piazza and by the Spanish Ministry of Science and Innovation through the Ramon y Cajal Research Fellowship (RYC2018-024284-I) awarded to Marina Kalashnikova. This research was supported by the Basque Government through the BERC 2022-2025 program and by the Spanish State Research Agency through BCBL Severo Ochoa excellence accreditation CEX2020-001010-S. This research was also supported by the Spanish Ministry of Economy and Competitiveness (PID2020-113926GB-I00 awarded to Clara D. Martin) and by the European Research Council under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement 819093 awarded to Clara D. Martin)

The phonetics of second language learning and bilingualism

This chapter provides an overview of major theories and findings in the field of second language (L2) phonetics and phonology. Four main conceptual frameworks are discussed and compared: the Perceptual Assimilation Model-L2, the Native Language Magnet Theory, the Automatic Selection Perception Model, and the Speech Learning Model. These frameworks differ in terms of their empirical focus, including the type of learner (e.g., beginner vs. advanced) and target modality (e.g., perception vs. production), and in terms of their theoretical assumptions, such as the basic unit or window of analysis that is relevant (e.g., articulatory gestures, position-specific allophones). Despite the divergences among these theories, three recurring themes emerge from the literature reviewed. First, the learning of a target L2 structure (segment, prosodic pattern, etc.) is influenced by phonetic and/or phonological similarity to structures in the native language (L1). In particular, L1-L2 similarity exists at multiple levels and does not necessarily benefit L2 outcomes. Second, the role played by certain factors, such as acoustic phonetic similarity between close L1 and L2 sounds, changes over the course of learning, such that advanced learners may differ from novice learners with respect to the effect of a specific variable on observed L2 behavior. Third, the connection between L2 perception and production (insofar as the two are hypothesized to be linked) differs significantly from the perception-production links observed in L1 acquisition. In service of elucidating the predictive differences among these theories, this contribution discusses studies that have investigated L2 perception and/or production primarily at a segmental level. In addition to summarizing the areas in which there is broad consensus, the chapter points out a number of questions which remain a source of debate in the field today.https://drive.google.com/open?id=1uHX9K99Bl31vMZNRWL-YmU7O2p1tG2wHhttps://drive.google.com/open?id=1uHX9K99Bl31vMZNRWL-YmU7O2p1tG2wHhttps://drive.google.com/open?id=1uHX9K99Bl31vMZNRWL-YmU7O2p1tG2wHAccepted manuscriptAccepted manuscrip

THE RELATIONSHIP BETWEEN ACOUSTIC FEATURES OF SECOND LANGUAGE SPEECH AND LISTENER EVALUATION OF SPEECH QUALITY

Second language (L2) speech is typically less fluent than native speech, and differs from it phonetically. While the speech of some L2 English speakers seems to be easily understood by native listeners despite the presence of a foreign accent, other L2 speech seems to be more demanding, such that listeners must expend considerable effort in order to understand it. One reason for this increased difficulty may simply be the speaker’s pronunciation accuracy or phonetic intelligibility. If a L2 speaker’s pronunciations of English sounds differ sufficiently from the sounds that native listeners expect, these differences may force native listeners to work much harder to understand the divergent speech patterns. However, L2 speakers also tend to differ from native ones in terms of fluency – the degree to which a speaker is able to produce appropriately structured phrases without unnecessary pauses, self-corrections or restarts. Previous studies have shown that measures of fluency are strongly predictive of listeners’ subjective ratings of the acceptability of L2 speech: Less fluent speech is consistently considered less acceptable (Ginther, Dimova, & Yang, 2010). However, since less fluent speakers tend also to have less accurate pronunciations, it is unclear whether or how these factors might interact to influence the amount of effort listeners exert to understand L2 speech, nor is it clear how listening effort might relate to perceived quality or acceptability of speech. In this dissertation, two experiments were designed to investigate these questions