Illusory Vowels Research Articles

Variability in English-Spanish bilingual phonotactics

Spanish prohibits initial sC clusters. Past studies have reported that this phonotactic restriction results in the perception of an illusory /e/, ‘repairing’ the illicit sequence (e.g., spid perceived as espid). Because English allows sC clusters, English-Spanish bilinguals are confronted with conflicting phonotactic systems. The present study investigated if this locus of phonotactic conflict yields bilingual variability (i.e., non-monolingual-like language behavior). Spanish monolinguals and English-Spanish bilinguals performed a nonce word judgment task, whereby they assigned acceptability ratings to sC-initial nonce words. Monolinguals were highly unaccepting of sC-initial words, whereas bilinguals were more likely to accept them as phonotactically licit, showing evidence of bilingual variability. The bilingual variability was constrained by English phonotactics, as sC clusters were rated as significantly more acceptable than other illicit onset clusters that are illicit in both languages. Furthermore, the monolinguals failed to show evidence of an illusory vowel effect, highlighting the importance of task type in phonotactic perception studies.

The relationship between perception and production of illusory vowels in a second language

Korean learners of English are known to repair consonant clusters, which are not allowed in their native language, with an epenthetic vowel [ɨ]. The purpose of the present study is to examine whether the perception–production link of such an illusory vowel in a second language (L2) is only within and not across processing levels, as proposed in a previous study regarding L2 segments. We assessed the perception and production of English onset clusters by Korean learners and native English speakers at the prelexical (AX discrimination and pseudoword read-aloud tasks) and lexical (lexical decision and picture-naming tasks) levels, using the same participants and stimuli across the tasks. Results showed that accuracy in not producing an epenthetic vowel between the two consonants of onset cluster was not significantly associated with accurate perception of the cluster either within or across processing levels. The results suggest that production and perception accuracy in L2 phonotactics are independent to a certain extent.

Redeploying appendices in L2 phonology

In this paper, we explore aspects of the production and perception of certain consonant clusters (in particular s + C clusters) in second language learners. We administered perception tasks (ABX and non-word transcription) and production tasks (reading, picture-based discussion, and elicited imitation) to native speakers of Persian and Arabic, and compare their results to those in previously published studies of other L1s. We will arrive at two broad conclusions. The first is that many subjects who demonstrate non-targetlike production of consonantal sequences by producing epenthetic vowels between the consonants are not hearing an illusory vowel in perception tasks. Thus, non-nativelike production is not always reflective of non-nativelike perception; non-nativelike production is not always caused by non-nativelike perception. Our second conclusion is that the locus of explanation for the accurate perception in subjects whose L1s lack s + C clusters is the presence or absence in the L1 of right-edge syllabic appendices. L1s which do not license appendices (Japanese, Brazilian Portuguese) will have difficulty perceiving L2 English s + C sequences, while L1s which do license appendices (Persian, Arabic) will not have difficulty perceiving L2 English s + C strings.

Multiple Sources of Surprisal Affect Illusory Vowel Epenthesis.

Illusory epenthesis is a phenomenon in which listeners report hearing a vowel between a phonotactically illegal consonant cluster, even in the complete absence of vocalic cues. The present study uses Japanese as a test case and investigates the respective roles of three mechanisms that have been claimed to drive the choice of epenthetic vowel—phonetic minimality, phonotactic predictability, and phonological alternations—and propose that they share the same rational goal of searching for the vowel that minimally alters the original speech signal. Additionally, crucial assumptions regarding phonological knowledge held by previous studies are tested in a series of corpus analyses using the Corpus of Spontaneous Japanese. Results show that all three mechanisms can only partially account for epenthesis patterns observed in language users, and the study concludes by discussing possible ways in which the mechanisms might be integrated.

Japanese Perceptual Epenthesis is Modulated by Transitional Probability.

Perceptual epenthesis is the perception of illusory vowels in consonantal sequences that violate native phonotactics. The consensus has been that each language has a single, predictable candidate for perceptual epenthesis, that vowel which is most minimal (i.e., shortest and/or quietest). However, recent studies have shown that alternate epenthetic vowels can be perceived when the perceptual epenthesis of the minimal vowel would violate native co-occurrence restrictions. We propose a potential explanation for these observed patterns: speech perception, and thus also vowel perceptual epenthesis, is modulated by transitional probability whereby epenthetic vowels must conform to the language specific expectations of the listener. To test this explanation, we present two experiments examining perceptual epenthesis of two Japanese vowels-/u/ and /i/-against their transitional probability in CV sequences. In Experiment 1, Japanese listeners assigned VCCV tokens to VCuCV and VCiCV categories. In Experiment 2, participants discriminated VCCV tokens from VCuCV and VCiCV tokens. The results show that sequences where /i/ is transitionally probable are more likely to elicit /i/ perceptual epenthesis.

Illusory vowels in Spanish–English sequential bilinguals: Evidence that accurate L2 perception is neither necessary nor sufficient for accurate L2 production

Spanish native speakers are known to pronounce onset /sC/ clusters in English with a prothetic vowel, as in esport for sport, due to their native language phonotactic constraints. We assessed whether accurate production of e.g. spi instead of espi was related to accurate perceptual discrimination of this contrast in second language (L2) speech of Spanish–English sequential bilinguals. A same–different discrimination task in stimulus pairs such as spi–espi assessed speech perception and a phonemic verbal fluency task elicited speech production. Logistic mixed model regressions revealed significant differences in accuracy between the bilinguals and the English monolinguals, although some bilinguals performed within the monolingual range. For the production task, but not for the perception task, bilinguals with more exposure to English and greater grammatical knowledge of English performed significantly more accurately than those with less exposure and lower grammatical knowledge. There was no significant correlation between production accuracy and perception accuracy. Through examining phonotactic constraints, these results expand a growing body of research into single sounds which suggests dissociations between L2 perception and production. In contrast to predictions made by L2 speech models, the findings indicate that accurate L2 perception is neither necessary nor sufficient for accurate L2 production, and instead are interpreted to indicate that the two capacities recruit different executive control mechanisms and are acquired – at least to a certain extent – independently in L2 acquisition.

I’ve heard that one before: Phonetic reduction in speech production as a possible contributing factor in perceptual illusory vowel effects

AbstractThis study probed the relationship between productive phonotactic repair and speech production, by asking whether the natural variability found in speech, through phonetic reduction, may include apparent illicit sequences requiring repair, even though the target words are licit. Spanish productively repairs word-initial /s/-consonant clusters (#sC) with a prothetic [e] in both production and perception. We asked whether the initial vowel in Spanish #VsC words likeespalda‘back’ is prone to reduction, and whether or not /e/, which matches the default repair vowel, is more susceptible to reduction than other vowels (e.g. inaspirina‘aspirin’) due to its predictability. We explore these hypotheses in the speech of 11 speakers of Andalusian Spanish who produced #VsC words in isolation. Initial vowels showed lower intensity, greater devoicing, and less modal voicing compared to control #pVs-initial words, and initial /e, i, o/ were occasionally deleted, leading to the occurrence of apparently illicit sequences in actual speech, e.g.espaldaproduced as [spalda]. However, evidence that the default vowel, [e], was reduced more than other vowels was weak. These results suggest that variation in speech may contribute to the well-known illusory vowel effects, where listeners perceive illicit sequences as though the repair vowel had been present.

Influence of L2 English phonotactics in L1 Brazilian Portuguese illusory vowel perception

This study examines potential changes to L1 (Brazilian Portuguese, BP) perception of phonotactic structure as a function of L2 (English) experience. Syllables with a coda stop violate syllable structure constraints in BP, but are licit in English. As a result, BP monolinguals perceive an illusory /i/ after an illicit coda (e.g., ob/i/ter ‘to obtain’). To understand the effects on L1 perception when the L2 phonology allows a syllabic structure that is illicit in the L1, we tested 15 L1 speakers of BP in an L2 English immersion setting. In separate BP and English sessions, participants completed an explicit metalinguistic vowel identification task and two ABX tasks, with one ABX task designed to tap lower-level processing and the other, higher-level phonological processing. Our analysis reveals that, while not fully target-like in L2 English, the bilinguals’ perception data in both languages contrast sharply with existing monolingual BP data. This is the case whether participants employ what we assume here to be metalinguistic strategies, lower-level encoding strategies, or higher-level encoding strategies in perception. Based on this pattern of results, we conclude that the data provide evidence of L2 phonotactic influence in L1 perception.

On the relation between speech perception and loanword adaptation

Loanword adaptation has been claimed to provide a unique window onto the relation between speech perception and the phonological grammar. This paper focuses on whether the ‘illusory vowel’ effect—in which the presence/absence of a vowel is poorly discriminated within an illicit cluster—is sufficient to explain why vowel epenthesis is the preferred repair for medial clusters in Korean loanword adaptation. A cross-linguistic discrimination experiment revealed a causative role of the stop release burst (or other audible frication noise) in the perception of an illusory vowel; in some cases, perception alone explains vowel epenthesis in loanword adaptation. A follow-up, identification experiment showed that Koreans’ perceptual similarity judgements do not match up with the adaptation pattern for stop-nasal clusters (e.g. pakna), although they do for fricative-stop and stop-stop clusters (e.g. paska, pakta). This finding is problematic for a purely perceptual account of loanword adaptation. The paper sketches a Bayesian account of Korean speech perception that integrates top-down phonotactic likelihood and bottom-up acoustic match and is able to explain the experimental results. It closes with some speculation on the role of the Preservation Principle versus perception in loanword adaptation.

Now you hear it, now you don't: Malleable illusory vowel effects in Spanish–English bilinguals

Spanish speakers tend to perceive an illusory [e] preceding word-initial [s]-consonant sequences, e.g., perceiving [stið] as [estið] (Cuetos, Hallé, Domínguez & Segui, 2011), but this illusion is weaker for Spanish speakers who know English, which lacks the illusion (Carlson, Goldrick, Blasingame & Fink, 2016). The present study aimed to shed light on why this occurs by assessing how a brief interval spent using English impacts performance in Spanish auditory discrimination and lexical decision. Late Spanish–English bilinguals’ pattern of responses largely matched that of monolinguals, but their response times revealed significant differences between monolinguals and bilinguals, and between bilinguals who had just completed tasks in English vs. Spanish. These results suggest that late bilinguals do not simply learn to perceive initial [s]-consonant sequences veridically, but that elements of both their phonotactic systems interact dynamically during speech perception, as listeners work to identify what it was they just heard.

The effect of ‘illusory vowels’ in Spanish-speaking second language learners of English

This paper shows that second-language (L2) spoken-word recognition is greatly influenced by differences between the native language (L1) and the second language (L2), possibly attributed to either L1-L2 syllable-structure or phonotactic differences. Spanish-speaking English learners (experimental group) and native English listeners (control group) completed an AXB task and a word-monitoring task in which they monitored /(ǝ)s+Consonant/-initial words in English. The results show a clear effect of L1 phonotactics, as the native speakers of English outperformed the Spanish group. These results indicate that L1-L2 syllable-structure differences or L1 phonotactics have pervasive consequences for spoken-word recognition, and effect that will be further explored in the discussion section of this paper.

Phonology modulates the illusory vowels in perceptual illusions: Evidence from Mandarin and English

Native speakers perceive illusory vowels when presented with sound sequences that do not respect the phonotactic constraints of their language (Dupoux, Kakehi, Hirose, Pallier, & Mehler, 1999; Kabak & Idsardi, 2007). There is, however, less work on the quality of the illusory vowel. Recently, it has been claimed that the quality of the illusory vowel is also modulated by the phonology of the language, and that the phenomenon of illusory vowels can be understood as a result of the listener reverse inferring the best parse of the underlying representation given their native language phonology and the acoustics of the input stream (Durvasula & Kahng, 2015). The view predicts that listeners are likely to hear different illusory vowels in different phonological contexts. In support of this prediction, we show through two perceptual experiments that Mandarin Chinese speakers (but not American English speakers) perceive different illusory vowels in different phonotactic contexts. Specifically, when presented with phonotactically illegal alveopalatal coda consonants, Mandarin speakers perceived an illusory /i/, but in illegal alveolar stop coda contexts, they perceived a /ə/.

THE PHONOLOGICAL ILLUSION: THE QUALITY AND NUMBER OF EPENTHETIC VOWELS

Adult speakers tend to have difficulties in perceiving non-native sequences of sounds as their percep­tion is influenced by the features of their L1 phonological system. For example, previous studies have shown that Japanese speakers perceptually insert an illusory vowel /u/ in consonant clusters, which are phonotoctically illegal structures in Japanese. While the phenomenon of phonological illusion also occurs in other languages, such as Brazilian Portuguese or Korean, the epenthetic vowels have been shown to be language-specific. Despite these findings, many questions concerning the number of illusory vowels possible in a language and their quality remain open. In this study we will present recent work on the topic and provide a critical comparison of those findings, concentrating on the role of context-sensitivity in the determination of the features of the illusory vowel.

THE PHONOLOGICAL ILLUSION: THE QUALITY AND NUMBER OF EPENTHETIC VOWELS

Adult speakers tend to have difficulties in perceiving non-native sequences of sounds as their percep­tion is influenced by the features of their L1 phonological system. For example, previous studies have shown that Japanese speakers perceptually insert an illusory vowel /u/ in consonant clusters, which are phonotoctically illegal structures in Japanese. While the phenomenon of phonological illusion also occurs in other languages, such as Brazilian Portuguese or Korean, the epenthetic vowels have been shown to be language-specific. Despite these findings, many questions concerning the number of illusory vowels possible in a language and their quality remain open. In this study we will present recent work on the topic and provide a critical comparison of those findings, concentrating on the role of context-sensitivity in the determination of the features of the illusory vowel.

Effects of first language processes and representations on second language perception: The case of vowel epenthesis by Japanese speakers

Aims and objectives/purpose/research questions: Japanese speakers are known to perceive “illusory vowels” within consonant clusters illicit in their language. The present study examines how this perceptual vowel epenthesis is affected by first language (L1) processes (restoration of vowels devoiced through Japanese high vowel devoicing), L1 representations (loanword representations in Japanese speakers’ lexicons), and proficiency in English. Design/methodology/approach: The participants judged the presence or absence of a mora (e.g., ム /mu/) in an auditorily presented English word (e.g., homesick). The 40 test items contained a heterosyllabic consonant cluster with four different voicing patterns to examine whether the vowel restoration process is related to vowel epenthesis. Twenty of the test items are frequently used as loanwords in Japanese, meaning that they are stored in the L1 lexicon with a vowel inserted inside the consonant cluster (e.g., /hoomusikku/). The other 20 are low-frequency items that are virtually nonwords for the non-native participants. Data and analysis: The vowel epenthesis rates and reaction times (RTs) were obtained from 14 introductory learners, 15 intermediate learners, and 19 native speakers. Findings/conclusions: The results show the main effects of Voice, Loanword Representation, and Proficiency, as well as the interaction among the three factors. Negative correlations between vowel epenthesis rates and RTs were also observed for the learners. The results indicate differential effects of vowel restoration and loanwords on perceptual epenthesis by learners of different proficiency levels. Originality: The present study was one of the first attempts to test the relation between proficiency and perceptual vowel epenthesis using real English words. Significance/implications: The findings demonstrate the robustness of L1 processes and representations in second language perception while substantiating the existing argument for early vowel epenthesis. They also raise questions regarding the effects of training and the role of native speaker input.

Illusory vowels in perceptual epenthesis: the role of phonological alternations

Listeners often perceive illusory vowels when presented with consonant sequences that violate phonotactic constraints in their language. Previous research suggests that the phenomenon motivates speech-perception models that incorporate surface phonotactic information and the acoustics of the speech tokens. In this article, inspired by Bayesian models of speech perception, we claim that the listener attempts to identify target phonemic representations during perception. This predicts that the phenomenon of perceptual illusions will be modulated not only by surface phonotactics and the acoustics of the speech tokens, but also by the phonological alternations of a language. We present the results of three experiments (an AX task, an ABX task and an identification task) with native Korean listeners, and native English listeners as a control group, showing that Korean listeners perceive different sets of illusory vowels in different phonological contexts, in accordance with the phonological processes of vowel deletion and palatalisation in the language.

The role of phrasal phonology in speech perception: What perceptual epenthesis shows us

Recent research using the phenomenon of illusory vowels has raised our awareness of the extent to which speech perception is modulated by the listener's native-language phonological knowledge. However, most of the focus has been limited to word-level phonological knowledge. In this article, we suggest that the perceptual system recruits segmental phonological knowledge that makes crucial reference to prosodic domains far beyond the word-level. We report the results from three identification experiments on Korean and American English participants. In accordance with their native-language phonotactic constraints at the level of the Intonational Phrase, Korean listeners unlike American English listeners hear more illusory vowels in stimuli containing the sequence of voiced stops followed by nasal consonants (e.g. [eɡma]) than those containing voiceless stops followed by nasal consonants (e.g. [ekma]). The results are interpreted as support for the view that speech perception makes crucial reference to the concept of reverse inference.

The Influence of L1 Constraints on L2 Sound Perception

This study investigated the influence of L1-specific constraints on L2 perception. In particular, we examined the effect of the unreleased coda constraint in L1 on Korean learners’ perception of word final palatal sibilants across two proficiency levels, i.e., low vs. high. Our findings from a perception experiment showed that Korean learners, especially the low group learners, tended to hear the illusory vowel /i/ after a word final palatal sibilant. Thus, the low group learners had a difficulty in discriminating the contrasts of /ʃ/ vs. /ʃi/, /ʧ/ vs. /ʧi/, and /ʤ/ vs. /ʤi/. According to the perception experiment, the low group learners’ illusory vowel perception rates increased as frication noise of the word final palatal sibilant got longer. Additionally, the low group learners were not influenced by the relative duration of the vowel /i/ in perceiving the vowel. Rather, their vowel responses were more likely to be influenced by the frication duration of a word final palatal sibilant. The study revealed that L1 constraints are significant factors influencing L2 perception.

Perceptual Vowel Insertion in English-based Nonsense Words by Korean Learners

This study explores the role of L1 constraints in sound perception in English-based nonsense words by Korean learners of English. Specifically, the study examined the effect of the unreleased coda constraint in Korean when perceiving word final palatal sibilants in English-based nonsense words. Korean learners in low and high levels of English proficiency participated in the study. The results showed that the learners with low proficiency levels in English were more likely to perceive the illusory vowel /i/ following a word final palatal sibilant in nonsense words. Their perception showed the influence of frication duration after a word final palatal sibilant. Compared to the high level learners, the low level learners were more sensitive to acoustic properties of frication noise of a word final palatal sibilant, yet incorrectly employed them as the cues to the vowel /i/. The high level learners showed a different pattern in that their perception was influenced by the relative duration of the vowel instead of frication duration. The results of the present study using English-based nonsense words indicate that Korean low-level learners of English are significantly under the influence of L1 constraints in L2 perception of word final palatal sibilants.

Hearing an Illusory Vowel in Noise: Suppression of Auditory Cortical Activity

Human hearing is constructive. For example, when a voice is partially replaced by an extraneous sound (e.g., on the telephone due to a transmission problem), the auditory system may restore the missing portion so that the voice can be perceived as continuous (Miller and Licklider, 1950; for review, see Bregman, 1990; Warren, 1999). The neural mechanisms underlying this continuity illusion have been studied mostly with schematic stimuli (e.g., simple tones) and are still a matter of debate (for review, see Petkov and Sutter, 2011). The goal of the present study was to elucidate how these mechanisms operate under more natural conditions. Using psychophysics and electroencephalography (EEG), we assessed simultaneously the perceived continuity of a human vowel sound through interrupting noise and the concurrent neural activity. We found that vowel continuity illusions were accompanied by a suppression of the 4 Hz EEG power in auditory cortex (AC) that was evoked by the vowel interruption. This suppression was stronger than the suppression accompanying continuity illusions of a simple tone. Finally, continuity perception and 4 Hz power depended on the intactness of the sound that preceded the vowel (i.e., the auditory context). These findings show that a natural sound may be restored during noise due to the suppression of 4 Hz AC activity evoked early during the noise. This mechanism may attenuate sudden pitch changes, adapt the resistance of the auditory system to extraneous sounds across auditory scenes, and provide a useful model for assisted hearing devices.