Anne Cutler

Vowel glottalization, as voice quality variation, occurs at phrase edges or under prominence, often in conjunction with resolving onsetless syllables or vowel-vowel hiatus. This study examines whether and how voice quality in two varieties of English, American and Australian, is manifested at phrase edges and under prominence in vowels that are neither strictly initial nor final. Analyses of spectral and noise measures show that both varieties utilize voice quality to signal prominence and boundaries, even in non-edge contexts. Specifically, increased glottalization reflects stronger laryngeal articulation in line with domain-initial and prominence-induced strengthening. Conversely, phrase-final positions are characterized by phrase-final creak, which is often observed with phrase-final weakening. While both varieties show similar vowel glottalization usage, Australian English tends to use voice quality more extensively to mark focus than American English, with a greater overall tendency toward glottalization. This suggests that the impressionistic difference perceived in the general use of voice quality between the varieties (more robust glottalized vowels in Australian English) stems from differences in the use of glottalization in marking prosodic structure. These findings underscore the role of non-contrastive voice quality in shaping prosodic structure across varieties while also revealing dialect-specific interactions between phonetics and prosody in its manifestation.

Listeners adapt efficiently to new talkers by using lexical knowledge to resolve perceptual uncertainty. This adaptation has been widely observed, both in first (L1) and in second languages (L2). Here, adaptation was tested in both the L1 and L2 of speakers of Mandarin and English, two very dissimilar languages. A sound midway between /f/ and /s/ replacing either /f/ or /s/ in Mandarin words presented for lexical decision (e.g., bu4fa3 “illegal”; kuan1song1 “loose”) prompted the expected adaptation; it induced an expanded /f/ category in phoneme categorization when it had replaced /f/, but an expanded /s/ category when it had replaced /s/. Both L1 listeners and English-native listeners with L2 Mandarin showed this effect. In English, however (with e.g., traffic; insane), we observed adaptation in L1 but not in L2; Mandarin-native listeners, despite scoring highly in the English lexical decision training, did not adapt their category boundaries for /f/ and /s/. Whether the ambiguous sound appeared syllable-initially (as in Mandarin phonology) versus word-finally (providing more word identity information) made no difference. Perceptual learning for talker adaptation is language-specific in that successful lexically guided adaptation in one language does not guarantee adaptation in other known languages; the enabling conditions for adaptation may be multiple and diverse.

The automatic retuning of phoneme categories to better adapt to the speech of a novel talker has been extensively documented across various (neurotypical) populations, including both adults and children. However, no studies have examined auditory perceptual learning effects in populations atypical in perceptual, social, and language processing for communication, such as populations with autism. Employing a classic lexically‐guided perceptual learning paradigm, the present study investigated perceptual learning effects in Australian English autistic and non‐autistic adults. The findings revealed that automatic attunement to existing phoneme categories was not activated in the autistic group in the same manner as for non‐autistic control subjects. Specifically, autistic adults were able to both successfully discern lexical items and to categorize speech sounds; however, they did not show effects of perceptual retuning to talkers. These findings may have implications for the application of current sensory theories (e.g., Bayesian decision theory) to speech and language processing by autistic individuals.Lay Summary: Lexically guided perceptual learning assists in the disambiguation of speech from a novel talker. The present study established that while Australian English autistic adult listeners were able to successfully discern lexical items and categorize speech sounds in their native language, perceptual flexibility in updating speaker‐specific phonemic knowledge when exposed to a novel talker was not available. Implications for speech and language processing by autistic individuals as well as current sensory theories are discussed.

As many distributional learning (DL) studies have shown, adult listeners can achieve discrimination of a difficult non-native contrast after a short repetitive exposure to tokens falling at the extremes of that contrast. Such studies have shown using behavioural methods that a short distributional training can induce perceptual learning of vowel and consonant contrasts. However, much less is known about the neurological correlates of DL, and few studies have examined non-native lexical tone contrasts. Here, Australian-English speakers underwent DL training on a Mandarin tone contrast using behavioural (discrimination, identification) and neural (oddball-EEG) tasks, with listeners hearing either a bimodal or a unimodal distribution. Behavioural results show that listeners learned to discriminate tones after both unimodal and bimodal training; while EEG responses revealed more learning for listeners exposed to the bimodal distribution. Thus, perceptual learning through exposure to brief sound distributions (a) extends to non-native tonal contrasts, and (b) is sensitive to task, phonetic distance, and acoustic cue-weighting. Our findings have implications for models of how auditory and phonetic constraints influence speech learning.

Many different prosodic cues can help listeners predict upcoming speech. However, no research to date has assessed listeners’ processing of preceding prosody from different speakers. The present experiments examine (1) whether individual speakers (of the same language variety) are likely to vary in their production of preceding prosody; (2) to the extent that there is talker variability, whether listeners are flexible enough to use any prosodic cues signaled by the individual speaker; and (3) whether types of prosodic cues (e.g., F0 versus duration) vary in informativeness. Using a phoneme-detection task, we examined whether listeners can entrain to different combinations of preceding prosodic cues to predict where focus will fall in an utterance. We used unsynthesized sentences recorded by four female native speakers of Australian English who happened to have used different preceding cues to produce sentences with prosodic focus: a combination of pre-focus overall duration cues, F0 and intensity (mean, maximum, range), and longer pre-target interval before the focused word onset (Speaker 1), only mean F0 cues, mean and maximum intensity, and longer pre-target interval (Speaker 2), only pre-target interval duration (Speaker 3), and only pre-focus overall duration and maximum intensity (Speaker 4). Listeners could entrain to almost every speaker’s cues (the exception being Speaker 4’s use of only pre-focus overall duration and maximum intensity), and could use whatever cues were available even when one of the cue sources was rendered uninformative. Our findings demonstrate both speaker variability and listener flexibility in the processing of prosodic focus.

How do speakers of languages with different intonation systems produce and perceive prosodic junctures in sentences with identical structural ambiguity? Native speakers of English and of Mandarin produced potentially ambiguous sentences with a prosodic juncture either earlier in the utterance (e.g., “He gave her # dog biscuits,” “他给她#狗饼干 ”), or later (e.g., “He gave her dog # biscuits,” “他给她狗 #饼干 ”). These productiondata showed that prosodic disambiguation is realised very similarly in the two languages, despite some differences in the degree to which individual juncture cues (e.g., pausing) were favoured. In perception experiments with a new disambiguation task, requiring speeded responses to select the correct meaning for structurally ambiguous sentences, language differences in disambiguation response time appeared: Mandarin speakers correctly disambiguated sentences with earlier juncture faster than those with later juncture, while English speakers showed the reverse. Mandarin-speakers with L2 English did not show their native-language response time pattern when they heard the English ambiguous sentences. Thus even with identical structural ambiguity and identically cued production, prosodic juncture perception across languages can differ.

Listeners often experience cocktail-party situations, encountering multiple ongoing conversations while tracking just one. Capturing the words spoken under such conditions requires selective attention and processing, which involves using phonetic details to discern phonological structure. How do bilinguals accomplish this in L1-L2 competition? We addressed that question using a dichotic listening task with fluent Malayalam-English bilinguals, in which they were presented with synchronized nonce words, one in each language in separate ears, with competing onsets of a labial stop (Malayalam) and a labial fricative (English), both voiced or both voiceless. They were required to attend to the Malayalam or the English item, in separate blocks, and report the initial consonant they heard. We found that perceptual intrusions from the unattended to the attended language were influenced by voicing, with more intrusions on voiced than voiceless trials. This result supports our proposal for the feature specification of consonants in Malayalam-English bilinguals, which makes use of privative features, underspecification and the “standard approach” to laryngeal features, as against “laryngeal realism”. Given this representational account, we observe that intrusions result from phonetic properties in the unattended signal being assimilated to the closest matching phonological category in the attended language, and are more likely for segments with a greater number of phonological feature specifications.

Prominence, the expression of informational weight within utterances, can be signaled by prosodic highlighting (head-prominence, as in English) or by position (as in Korean edge-prominence). Prominence confers processing advantages, even if conveyed only by discourse manipulations. Here we compared processing of prominence in English and Korean, using a task that indexes processing success, namely recognition memory. In each language, participants’ memory was tested for target words heard in sentences in which they were prominent due to prosody, position, both or neither. Prominence produced recall advantage, but the relative effects differed across language. For Korean listeners the positional advantage was greater, but for English listeners prosodic and syntactic prominence had equivalent and additive effects. In a further experiment semantic and phonological foils tested depth of processing of the recall targets. Both foil types were correctly rejected, suggesting that semantic processing had not reached the level at which word form was no longer available. Together the results suggest that prominence processing is primarily driven by universal effects of information structure; but language-specific differences in frequency of experience prompt different relative advantages of prominence signal types. Processing efficiency increases in each case, however, creating more accurate and more rapidly contactable memory representations.