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There is a large consensus (e.g., Cristia, Foushee, Aravena-Bravo, Cychosz, Scaff & Casillas, 2023; Kidd & Garcia, 2022) that diversification in language acquisition research is needed. Cristia et al. (2023) convincingly argue for studying language acquisition in rural populations and recommend combining observational and experimental approaches in doing so. In this commentary, we identify that diversification efforts must also include children growing up in non-western urban societies and that combining experiments with more easy-to-obtain data on language exposure can be a solid method to start with.

Theories of phonology claim variously that phonological elements are either innate or emergent, and either substance-full or substance-free. A hitherto underdeveloped source of evidence for choosing between the four possible combinations of these claims lies in showing precisely how a child can acquire phonological elements. This article presents computer simulations that showcase a learning algorithm with which the learner creates phonological elements from a large number of sound–meaning pairs. In the course of language acquisition, phonological features gradually emerge both bottom-up and top-down, that is, both from the phonetic input (i.e., sound) and from the semantic or morphological input (i.e., structured meaning). In our computer simulations, the child's phonological features end up with emerged links to sounds (phonetic substance) as well as with emerged links to meanings (semantic substance), without containing either phonetic or semantic substance. These simulations therefore show that emergent substance-free phonological features are learnable. In the absence of learning algorithms for linking innate features to the language-specific variable phonetic reality, as well as the absence of learning algorithms for substance-full emergence, these results provide a new type of support for theories of phonology in which features are emergent and substance-free.

Lateral vocalisation is assumed to arise from changes in coronal articulation but is typically characterised perceptually without linking the vocalised percept to a coronal articulation. Therefore, we examined how listeners' perception of coda /l/ as vocalised relates to coronal closure. Perceptual stimuli were acquired by recording laterals produced by six speakers of Australian English using electromagnetic articulography (EMA). Tongue tip closure was monitored for each lateral in the EMA data. Increased incidence of incomplete coronal closure was found in coda /l/ relative to onset /l/. Having verified that the dataset included /l/ tokens produced with incomplete coronal closure—a primary articulatory cue of vocalised /l/—we conducted a perception study in which four highly experienced auditors rated each coda /l/ token from vocalised (3) to non-vocalised (0). An ordinal mixed model showed that increased tongue tip (TT) aperture and delay correlated with vocalised percept, but auditors ratings were characterised by a lack of inter-rater reliability. While the correlation between increased TT aperture, delay, and vocalised percept shows that there is some reliability in auditory classification, variation between auditors suggests that listeners may be sensitive to different sets of cues associated with lateral vocalisation that are not yet entirely understood.

A survey of diversity in leading language acquisition journals revealed that only 2% of the 7,000+ languages of the world are represented. With a long-term aim of empowering researchers everywhere to contribute to this literature, we organized the First Truly Global /L+/ International Summer/Winter School on Language Acquisition (/L+/). /L+/ was a free 5-day virtual school that facilitated the interchange of expertise among early career researchers about all levels of language development in monolingual and multilingual contexts. Our paper provides an overview of organizing /L+/, the measures we took to ensure inclusivity, and qualitative and quantitative analyses of attendees' experiences. We asked for volunteers through the LangVIEW consortium resulting in a diverse organization team from under-represented areas: Sub-Saharan Africa, South and Southeast Asia, and Central and South America. To promote inclusivity, we (1) employed asynchronous and synchronous elements across three time zones; (2) provided closed captions for lectures and international sign interpretation for live sessions; (3) issued a code of conduct. For each time zone, an algorithm selected 120 participants (80% from traditionally under-represented regions) and 61 countries were represented. A post-school questionnaire revealed that 99% of attendees enjoyed taking part in /L+/. However, qualitative comments suggested that there were issues in duration, contents and scheduling. Although much remains to be done to promote inclusivity in linguistic research, we hope our school will contribute to empowering researchers to investigate and publish on language acquisition in their home languages.

Infants diagnosed with autism spectrum disorder (autism) have difficulty engaging in social communication and interactions with others and often experience language impairment. The use of infant-directed speech (IDS), which is the speech register used when interacting with infants, is associated with infant language and socio-communicative development. The aim of this study was twofold; the first aim was to scope the literature to determine if evidence exists for differences between the IDS caregivers use to infants at high-risk or those later diagnosed with autism, and the IDS typically spoken to neurotypical infants. The second aim was to investigate if any IDS characteristics used by caregivers of high-risk or diagnosed infant populations predicted language development. Twenty-six studies were included and provided evidence that high-risk and later diagnosed infants are exposed to similar amounts of IDS as their neurotypical peers. There is evidence, however, that the IDS used with high-risk and later diagnosed infants may comprise shorter utterances, more action-directing content, fewer questions, more attention bids, and more follow-in commenting. There is also evidence that more attention bids and follow-in commenting used to infants at high risk or those later diagnosed with autism were associated with better language abilities longitudinally.

Although both fathers and mothers speak differently in infant-directed speech (IDS) compared to adult-directed speech (ADS), the acoustic characteristics of present-day paternal IDS are still insuf...

Vowel contrasts may be reduced or neutralized before coda laterals in English [Bernard (1985). The Cultivated Australian: Festschrift in Honour of Arthur Delbridge, pp. 319–332; Labov, Ash, and Boberg (2008). The Atlas of North American English, Phonetics and Sound Change (Gruyter Mouton, Berlin); Palethorpe and Cox (2003). International Seminar on Speech Production (Macquaire University, Sydney, Australia)], but the acoustic characteristics of vowel-lateral interaction in Australian English (AusE) rimes have not been systematically examined. Spectral and temporal properties of 16 pre-lateral and 16 pre-obstruent vowels produced by 29 speakers of AusE were compared. Acoustic vowel similarity in both environments was captured using random forest classification and hierarchical cluster analysis of the first three DCT coefficients of F1, F2, and F3, and duration values. Vowels preceding /l/ codas showed overall increased confusability compared to vowels preceding /d/ codas. In particular, reduced spectral contrast was found for the rime pairs /iːl-ɪl/ (feel-fill), /ʉːl-ʊl/ (fool-full), /əʉl-ɔl/ (dole-doll), and /aeɔl-ael/ (howl-Hal). Potential articulatory explanations and implications for sound change are discussed.

Here we present AusKidTalk [1], an audio-visual (AV) corpus of Australian children’s speech collected to facilitate the development of speech based technological solutions for children. It builds upon the technology and expertise developed through the collection of an earlier corpus of Australian adult speech, AusTalk [2,3]. This multi-site initiative was established to remedy the dire shortage of children’s speech corpora in Australia and around the world that are sufficiently sized to train accurate automated speech processing tools for children. We are collecting ~600 hours of speech from children aged 3–12 years that includes single word and sentence productions as well as narrative and emotional speech. In this paper, we discuss the key requirements for AusKidTalk and how we designed the recording setup and protocol to meet them. We also discuss key findings from our feasibility study of the recording protocol, recording tools, and user interface.

In Australian English rimes, coarticulation between coda /l/ and its preceding vowel has the potential to attenuate cues that contribute to phonological vowel contrast. Therefore, vowel-/l/ coarticulation may increase ambiguity between prelateral vowels. We used a vowel identification task to test the effect of vowel-/l/ coarticulation on vowel disambiguation in perception. Listeners categorized vowels in /hVd/ and /hVl/ contexts. Results showed reduced accuracy of vowels before coda /l/ compared to coda /d/, showing that coda /l/ increases vowel disambiguation difficulty. In particular, reduced perceptual contrast was found for the rime pairs /ʉːl-ʊl, aeɔl-ael/ and /əʉl-ɔl/ (e.g., fool-full, howl-Hal, dole-doll). A second experiment tested the effect of reduced perceptual contrast on word recognition. Listeners identified minimal pairs contrasting key vowel pairs in the /CVl/ and /CVd/ contexts. Reduced accuracy and increased response time in /l/ contexts shows that coda /l/ hinders listeners’ ability to identify vowels. The implications of reduced perceptual vowel contrast for compensation for coarticulation and sound change are discussed.

Infants exploit acoustic boundaries to perceptually organize phrases in speech. This prosodic parsing ability is well-attested and is a cornerstone to the development of speech perception and grammar. However, infants also receive linguistic input in child songs. This study provides evidence that infants parse songs into meaningful phrasal units and replicates previous research for speech. Six-month-old Dutch infants (n = 80) were tested in the song or speech modality in the head-turn preference procedure. First, infants were familiarized to two versions of the same word sequence: One version represented a well-formed unit, and the other contained a phrase boundary halfway through. At test, infants were presented two passages, each containing one version of the familiarized sequence. The results for speech replicated the previously observed preference for the passage containing the well-formed sequence, but only in a more fine-grained analysis. The preference for well-formed phrases was also observed in the song modality, indicating that infants recognize phrase structure in song. There were acoustic differences between stimuli of the current and previous studies, suggesting that infants are flexible in their processing of boundary cues while also providing a possible explanation for differences in effect sizes.

Voices can be characterized by their fundamental frequency as well as by speech timbre characteristics, such as formant frequencies. While infants' responses to fundamental frequency characteristics are well established, very little is known about how infants respond to changes in formant frequencies. This study tested whether 6-month-old infants prefer listening to speech with raised formant frequencies over speech with lowered formant frequencies. Naturally spoken utterances were acoustically manipulated to render raised-formant and lowered-formant stimuli that only differed in the formant frequencies, while keeping fundamental frequency and other acoustic characteristics constant. Infants in an infant-controlled listening procedure listened longer to the raised-formant than to the lowered-formant stimuli. These results provide the first evidence that infants distinguish and show preferences for variations in formant frequencies in adult speech.

Listeners rely on multiple acoustic cues to recognize any phoneme. The relative contribution of these cues to listeners' perception is typically inferred from listeners' categorization of sounds in a two-alternative forced-choice task. Here we advocate the use of an evidence accumulation model to analyze categorization as well as response time data from such cue weighting paradigms in terms of the processes that underlie the listeners' categorization. We tested 30 Dutch listeners on their categorization of speech sounds that varied between typical /a/ and /a/ in vowel quality (F1 and F2) and duration. Using the linear ballistic accumulator model, we found that the changes in spectral quality and duration lead to changes in the speed of information processing, and the effects were larger for spectral quality. In addition, for stimuli with atypical spectral information, listeners accumulate evidence faster for /a/ compared to /ad. Finally, longer durations of sounds did not produce longer estimates of perceptual encoding time. Our results demonstrate the utility of evidence accumulation models for learning about the latent processes that underlie phoneme categorization. The implications for current theory in speech perception as well as future directions for evidence accumulation models are discussed. (C) 2016 Elsevier Ltd. All rights reserved.

Most children listen to speech as their primary source of communication. Yet which language they learn depends on where they grow up (Cutler, 2012): for instance, babies growing up in the Netherlands will grow up speaking Dutch while those growing up in China might master Mandarin. All these languages are markedly different: they differ in the repertoire of speech sounds, in the use of suprasegmental information (whether acoustic variations above the level of phonetics/phonemes can differentiate between words, such as word stress and tone), and in phonotactic information (which phoneme combinations are permissible in a language or not). When infants are born, their natural preferences and abilities in speech perception are hardly shaped by their native language. In other words, newborns are considered 'universal listeners' (Kuhl et al., 2008). Yet through repeated exposure to their native language, cross-linguistic differences between infants soon become apparent, which suggests that the first year of life sets the scene for language-specific listening. This chapter makes clear that speech perception is not a trivial task: speech is like a stream of sounds embedded in words combining into phrases, with no pauses that reliably signal where words begin or end (See Figure 1). Fortunately, speech contains and conveys cues to many linguistic elements simultaneously. Speech perception is the process of extracting cues from the speech stream, to recognise the message that a speaker is conveying. This process is further complicated by the fact that all speakers are different and therefore produce the cues slightly differently. In what follows next, we will first describe the input that children are exposed to (Section 15.1), before we turn to how children learn to recognise their native language from other acoustic signals (Section 15.2) and to decompose into meaningful units: into sounds (Section 15.3), into suprasegmental units (Section 15.4), and finally, into words (Section 15.5). In Section 15.6 we discuss the development of speech perception in relation to speech exposure and brain maturation. In our concluding section (Section 15.6) we underscore the relevance of early speech perception skill as crucial for language acquisition. 15.1 What kind of speech do children hear? The primary source of speech is vocal fold vibration, resulting in voiced sounds with a fundamental frequency, which is perceived as pitch. Speech can also vary in amplitude, 1 1 = Utrecht University, 2 = University of Postdam, 3 = Macquarrie University 2 perceived as fluctuations in loudness, and in the duration of segments and phrases, which may signal speaking rate, among many other things. Figure 1: A plot to indicate that speech is a stream of sounds: a sound spectrogram of a Dutch utterance 'in speech, all words are glued together', with time on the x-axis, spectral frequencies from 0 -8000 Hz (signaling vowel and consonant properties) on the left y-axis, and fundamental frequencies (pitch information signaling intonation and word stress by means of the rising and falling line in the spectrogram) on the right y-axis. The tiers below the spectrogram show the speech stream segmented into relevant subunits of speech: the top tier shows how harmonics cluster to correspond to specific speech sounds segments. The second tier groups these segments into Dutch words. Note that pauses in the speech signal the onset of plosives (/k/, /p/, /t/); they do not align with the onset or offset of words. The third tier offers a translation of the words into English. Frequency, amplitude and duration are essential cues to suprasegmental structure, such as lexical stress, tone, and intonation of an entire utterance (Fry, 1955; Pierrehumbert, 1980; Beckman, 1986). To give an example from Figure 1: the second vowel in the Dutch word /əәlkaːr/ is typically higher, louder, and longer than the first, because the second but not the first syllable carries lexical stress. These suprasegmental cues also play a role in distinguishing between the two main segmental classes, as vowels are typically voiced, and louder and longer than consonants.

Hyper-articulation of vowel and consonant contrasts is often reported in infant-directed speech (IDS), but is not universal cross-linguistically, and may be a side-effect of speaking rate. This study investigated the voicing characteristics of the four-way oral stop voicing contrast in Nepali IDS. Both lead and lag time of word-onset/ɡ, ɡʱ, k, kʱ/were measured in the IDS and adult-directed speech (ADS) of 16 Nepali-speaking mothers. The lower prevalence of contrastive prevoicing and shorter lead times in IDS compared to ADS indicate hypo-articulated voicing contrasts. Shorter overall lag times in IDS suggest that stop consonants are less salient in IDS compared to ADS. These results cannot be explained as a side-effect of speaking rate, but rather suggest an increased salience for vowels compared to consonants within the IDS syllable. The implications for the acquisition of voicing contrasts are discussed.

Contains fulltext : 201120.pdf (Publisher’s version ) (Open Access) Bilingual children are often exposed to non-native speech through their parents. Yet, little is known about the relation between bilingual preschoolers' speech production and their speech input. The present study investigated the production of voice onset time (VOT) by Dutch-German bilingual preschoolers and their sequential bilingual mothers. The findings reveal an association between maternal VOT and bilingual children's VOT in the heritage language German as well as in the majority language Dutch. By contrast, no input-production association was observed in the VOT production of monolingual German-speaking children and monolingual Dutch-speaking children. The results of this study provide the first empirical evidence that non-native and attrited maternal speech contributes to the often-observed linguistic differences between bilingual children and their monolingual peers. 26 p.

This study assesses the effects of age and language exposure on VOT production in 29 simultaneous bilingual children aged 3;7 to 5;11 who speak German as a heritage language in the Netherlands. Dutch and German have a binary voicing contrast, but the contrast is implemented with different VOT values in the two languages. The results suggest that bilingual children produce ‘voiced’ plosives similarly in their two languages, and these productions are not monolingual-like in either language. Bidirectional cross-linguistic influence between Dutch and German can explain these results. Yet, the bilinguals seemingly have two autonomous categories for Dutch and German ‘voiceless’ plosives. In German, the bilinguals’ aspiration is not monolingual-like, but bilinguals with more heritage language exposure produce more target-like aspiration. Importantly, the amount of exposure to German has no effect on the majority language's ‘voiceless’ category. This implies that more heritage language exposure is associated with more language-specific voicing systems.

Children’s songs often contain rhyming words at phrase endings. In this study, we investigated whether infants can already recognize this phonological pattern in songs. Earlier studies using lists of spoken words were equivocal on infants’ spontaneous processing of rhymes (Hayes, Slater, & Brown, 2000; Jusczyk, Goodman, & Baumann, 1999). Songs, however, constitute an ecologically valid rhyming stimulus, which could allow for spontaneous processing of this phonological pattern in infants. Novel children’s songs with rhyming and non-rhyming lyrics using pseudo-words were presented to 35 9-month-old Dutch infants using the Headturn Preference Procedure. Infants on average listened longer to the non-rhyming songs, with around half of the infants however exhibiting a preference for the rhyming songs. These results highlight that infants have the processing abilities to benefit from their natural rhyming input for the development of their phonological abilities.

Contains fulltext : 177673.pdf (Publisher’s version ) (Open Access) Speech of late bilinguals has frequently been described in terms of cross-linguistic influence (CLI) from the native language (L1) to the second language (L2), but CLI from the L2 to the L1 has received relatively little attention. This article addresses L2 attainment and L1 attrition in voicing systems through measures of voice onset time (VOT) in two groups of Dutch-German late bilinguals in the Netherlands. One group comprises native speakers of Dutch and the other group comprises native speakers of German, and the two groups further differ in their degree of L2 immersion. The L1-German-L2-Dutch bilinguals (N = 23) are exposed to their L2 at home and outside the home, and the L1-Dutch-L2-German bilinguals (N = 18) are only exposed to their L2 at home. We tested L2 attainment by comparing the bilinguals' L2 to the other bilinguals' L1, and L1 attrition by comparing the bilinguals' L1 to Dutch monolinguals (N = 29) and German monolinguals (N = 27). Our findings indicate that complete L2 immersion may be advantageous in L2 acquisition, but at the same time it may cause L1 phonetic attrition. We discuss how the results match the predictions made by Flege's Speech Learning Model and explore how far bilinguals' success in acquiring L2 VOT and maintaining L1 VOT depends on the immersion context, articulatory constraints and the risk of sounding foreign accented. 36 p.

Infant-directed speech (IDS) is the speech register used when interacting with infants. Pitch contours are a salient aspect of IDS and facilitate infant language and socio-communicative development. Little research investigates pitch contours within the context of socio-communication or language deficits, such as infants at high-risk (HR) for Autism Spectrum Disorder (autism). The aim of this study was to characterise pitch contours used by mothers when interacting with HR infants compared to mothers interacting with low-risk (LR) infants. 18 mothers and their 12-month-old infant (12m, 6f) participated in 15-minute recorded interactions. Autism risk was assessed via parent and observer-report. Pearson product-moment correlations were performed to determine relationships between maternal pitch contours and autism risk. Increased risk for autism was associated with fewer utterances (r = -0.576, N = 18, p = 0.01) and fewer rising (r = -0.586, N = 18, p = 0.01), sinusoidal (r = -0.636, N = 18, p = 0.005), and flat contours (r = -0.679, N = 18, p = 0.01), and more complex (r = 0.584, N = 18, p = 0.01), rapid (r = 0.526, N = 18, p = 0.03), and u-shaped contours (r = 0.619, N = 18, p = 0.02). These preliminary data suggest that mothers of HR infants use different patterns of pitch contours than LR mothers. Further assessment of IDS used with HR infants is warranted to identify at what stage IDS patterns deviate between groups.

In behavioral tasks, previous research has found that advanced Spanish learners of Dutch rely on duration cues to distinguish Dutch vowels, while Dutch listeners rely on spectral cues. This study tested whether language-specific cue weighting is reflected in preattentive processing. The mismatch negativity (MMN) of Dutch and Spanish participants was examined in response to spectral and duration cues in Dutch vowels. The MMN at frontal and mid sites was weaker and peaked later at Fz for Spanish than for Dutch listeners for the spectrally cued contrasts, whereas both groups responded similarly to the duration cue. In line with overt categorization behavior, these MMN data indicate that preattentive cue weighting depends on the listeners' language experience.

Previous research has demonstrated that learners of English with different L1 backgrounds diverge from native speakers in their use of acoustic cues for the perception and production of vowel contrasts. This study investigated the use of two cues, i.e., vowel spectrum and duration, for the categorization of the Dutch /aː/-/ɑ/ contrast in three groups of listeners: L1-Dutch, L1-Spanish L2-Dutch, and L1-German listeners. Three aspects of vowel contrast perception were tested: the categorical nature of the listeners’ perceptual boundary, their cue weighting, and their use of the individual cues. Experience with the Dutch language played a role in the ability to perceptually distinguish the two vowel categories: Native Dutch listeners and Spanish learners of Dutch could categorize prototypical tokens of Dutch /aː/ and /ɑ/ more reliably than L1-German listeners without experience with the Dutch language. Native Dutch listeners had the most sharply defined boundary between the two categories. The results also show that language background strongly affects vowel perception: both L1-Dutch and L1-German listeners weight vowel spectrum heavier than vowel duration, whereas L1-Spanish L2-Dutch listeners favour vowel duration. L1-German listeners’ cue weighting can be explained in terms of the cross-linguistic comparison between German and Dutch vowels. L1-Spanish L2-Dutch listeners’ results have implications for theories of second language perception.

Distributional learning of speech sounds is learning from simply being exposed to frequency distributions of speech sounds in one’s surroundings. In laboratory settings, the mechanism has been reported to be discernible already after a few minutes of exposure, in both infants and adults. These “effects of distributional training” have traditionally been attributed to the difference in the number of peaks between the experimental distribution (two peaks) and the control distribution (one or zero peaks). However, none of the earlier studies fully excluded a possibly confounding effect of the dispersion in the distributions. Additionally, some studies with a non-speech control condition did not control for a possible difference between processing speech and non-speech. The current study presents an experiment that corrects both imperfections. Spanish listeners were exposed to either a bimodal distribution encompassing the Dutch contrast /ɑ/∼/a/ or a unimodal distribution with the same dispersion. Before and after training, their accuracy of categorization of [ɑ]- and [a]-tokens was measured. A traditionally calculated p-value showed no significant difference in categorization improvement between bimodally and unimodally trained participants. Because of this null result, a Bayesian method was used to assess the odds in favor of the null hypothesis. Four different Bayes factors, each calculated on a different belief in the truth value of previously found effect sizes, indicated the absence of a difference between bimodally and unimodally trained participants. The implication is that “effects of distributional training” observed in the lab are not induced by the number of peaks in the distributions.

Exaggeration of the vowel space in infant-directed speech (IDS) is well documented for English, but not consistently replicated in other languages or for other speech-sound contrasts. A second attested, but less discussed, pattern of change in IDS is an overall rise of the formant frequencies, which may reflect an affective speaking style. The present study investigates longitudinally how Dutch mothers change their corner vowels, voiceless fricatives, and pitch when speaking to their infant at 11 and 15 months of age. In comparison to adult-directed speech (ADS), Dutch IDS has a smaller vowel space, higher second and third formant frequencies in the vowels, and a higher spectral frequency in the fricatives. The formants of the vowels and spectral frequency of the fricatives are raised more strongly for infants at 11 than at 15 months, while the pitch is more extreme in IDS to 15-month olds. These results show that enhanced positive affect is the main factor influencing Dutch mothers’ realisation of speech sounds in IDS, especially to younger infants. This study provides evidence that mothers’ expression of emotion in IDS can influence the realisation of speech sounds, and that the loss or gain of speech clarity may be secondary effects of affect.

This study addresses the questions of whether listening to a bimodal distribution of vowels improves adult learners’ categorization of a difficult L2 vowel contrast and whether enhancing the acoustic differences between the vowels in the distribution yields better categorization performance. Spanish learners of Dutch were trained on a natural bimodal or an enhanced bimodal distribution of the Dutch vowels /ɑ/ and /aː/, with the average productions of the vowels or more extreme values as the endpoints respectively. Categorization improved for learners who listened to the enhanced distribution, which suggests that adults profit from input with properties similar to infant-directed speech.

In behavioral tasks, previous research has found that advanced Spanish learners of Dutch rely on duration cues to distinguish Dutch vowels, while Dutch listeners rely on spectral cues. This study tested whether language-specific cue weighting is reflected in preattentive processing. The mismatch negativity (MMN) of Dutch and Spanish participants was examined in response to spectral and duration cues in Dutch vowels. The MMN at frontal and mid sites was weaker and peaked later at Fz for Spanish than for Dutch listeners for the spectrally cued contrasts, whereas both groups responded similarly to the duration cue. In line with overt categorization behavior, these MMN data indicate that preattentive cue weighting depends on the listeners' language experience.

We investigate the influence of the stimulus range and the number of response categories on the location of perceptual boundaries. The F1 continuum between Spanish /i/ and /e/ was presented to Peruvian listeners in three ranges. Half of the listeners could classify the tokens as /i/ and /e/, the other half chose from the five Spanish vowels. A boundary shift between /i/ and /e/ was observed as a function of the stimulus range, which was larger when listeners were given only two response categories. These results are interpreted as an effect of listeners’ category expectations on speech perception.

The categorization of speech sounds is influenced by the preceding sound context. Specifically, listeners shift their boundary between two categories toward the values of the preceding sounds. Such boundary shifts are larger if listeners can respond with fewer categories than are actually present in the stimuli. This study investigates the influence of the stimulus range on boundary shifts between vowels and whether these shifts are smaller if listeners can choose from more categories than are present in the stimuli. The F1 continuum between Spanish /i/ and /e/ was presented to Peruvian listeners in three ranges. Half of the listeners responded with /i/ and /e/, the other half chose from the five Spanish vowels. Boundary shifts between /i/ and /e/ as a function of the stimulus range were observed, which were smaller when listeners could choose from five categories. In subsequent analyzes, the influence of the preceding sound context appeared smaller for listeners that could choose from five categories. Al...

First Published November 29, 2021 Dutch and German employ voicing contrasts, but Dutch lacks the ‘voiced’ dorsal plosive /ɡ/. We exploited this accidental phonological gap, measuring the presence of prevoicing and voice onset time durations during speech production to determine (1) whether preliterate bilingual Dutch–German and monolingual Dutch-speaking children aged 3;6–6;0 years generalized voicing to /ɡ/ in Dutch; and (2) whether there was evidence for featural cross-linguistic influence from Dutch to German in bilingual children, testing monolingual German-speaking children as controls. Bilingual and monolingual children’s production of /ɡ/ provided partial evidence for feature generalization: in Dutch, both bilingual and monolingual children either recombined Dutch voicing and place features to produce /ɡ/, suggesting feature generalization, or resorted to producing familiar /k/, suggesting segment-level adaptation within their Dutch phonological system. In German, bilingual children’s production of /ɡ/ was influenced by Dutch although the Dutch phoneme inventory lacks /ɡ/. This suggests that not only segments but also voicing features can exert cross-linguistic influence. Taken together, phonological features appear to play a crucial role in aspects of bilingual and monolingual children’s speech production. This work was supported by the Basque Government [BERC 2018-2021 program]; the Spanish State Research Agency [BCBL Severo Ochoa excellence accreditation SEV-2015-0490]; the European Union’s Horizon 2020 research and innovation program [Marie Skłodowska-Curie grant 843533]; and the National Science Foundation [BCS1349110; OISE 1545900].

In an investigation of contextual influences on sound categorization, 64 Peruvian Spanish listeners categorized vowels on an /i/ to /e/ continuum. First, to measure the influence of the stimulus range (broad acoustic context) and the preceding stimuli (local acoustic context), listeners were presented with different subsets of the Spanish /i/-/e/ continuum in separate blocks. Second, the influence of the number of response categories was measured by presenting half of the participants with /i/ and /e/ as responses, and the other half with /i/, /e/, /a/, /o/, and /u/. The results showed that the perceptual category boundary between /i/ and /e/ shifted depending on the stimulus range and that the formant values of locally preceding items had a contrastive influence. Categorization was less susceptible to broad and local acoustic context effects, however, when listeners were presented with five rather than two response options. Vowel categorization depends not only on the acoustic properties of the target stimulus, but also on its broad and local acoustic context. The influence of such context is in turn affected by the number of internal referents that are available to the listener in a task. Portions of this work were presented as “The interrelation between the stimulus range and the number of response categories in vowel categorization,” Proceedings of Interspeech 2010, Makuhari, Japan, September 2010, and “The interrelation between the stimulus range and the number of response categories in vowel categorization,” 2nd Pan-American/Iberian Meeting on Acoustics, Cancun, Mexico, November 2010. J. Acoust. Soc. Am. Volume 131, Issue 4, pp. 3079-3087 (2012); (9 pages)