Vowel Pairs Research Articles

This 'Pull’s as Hot as 'Hal'


 
 
 This paper investigates mergers of the DRESS-TRAP and FOOT-GOOSE vowels in pre-lateral position for speakers of diverse varieties of English in Melbourne, Australia. A total of 35 participants were recorded producing 22 words from a list representing 11 monophthongs in pre-t and pre-l position. The vowels were measured for F1, F2, and duration, from which Pillai scores were calculated. Variation due to the speakers’ variety of English was as predicted. Duration contrasts for both vowel pairs were present for most speakers as a way to differentiate the vowels when their formants overlapped. This was expected for FOOT-GOOSE but previously unreported for DRESS-TRAP.
 
 

Contrast and Conflict in Dutch Vowels.

The nature of phonological representations has been extensively studied in phonology and psycholinguistics. While full specification is still the norm in psycholinguistic research, underspecified representations may better account for perceptual asymmetries. In this paper, we report on a mismatch negativity (MMN) study with Dutch listeners who took part in a passive oddball paradigm to investigate when the brain notices the difference between expected and observed vowels. In particular, we tested neural discrimination (indicating perceptual discrimination) of the tense mid vowel pairs /o/-/ø/ (place contrast), /e/-/ø/ (labiality or rounding contrast), and /e/-/o/ (place and labiality contrast). Our results show (a) a perceptual asymmetry for place in the /o/-/ø/ contrast, supporting underspecification of [CORONAL] and replicating earlier results for German, and (b) a perceptual asymmetry for labiality for the /e/-/ø/ contrast, which was not reported in the German study. A labial deviant [ø] (standard /e/) yielded a larger MMN than a deviant [e] (standard /ø/). No asymmetry was found for the two-feature contrast. This study partly replicates a similar MMN study on German vowels, and partly presents new findings indicating cross-linguistic differences. Although the vowel inventory of Dutch and German is to a large extent comparable, their (morpho)phonological systems are different, which is reflected in processing.

Perception of English Tense and Lax Vowels based on the Mechanism of Selective Attention

This study examined how the mechanisms of selective attention operate in perceiving English tense and lax vowels by Korean speakers. Given that each language system differently operates these mechanisms, the study predicted that Korean speakers would show poorer performance in back vowel pairs than the front ones and differently employ the acoustic cue in discriminating those pairs regarding the different vowel duration caused by following contrastive voicing consonants. For this, two different types of perception tests were carried out. The results demonstrated as follows. First, overall correct rates were much higher in the 4I-oddity test than in the identification test, which indicated higher sensitivity to the acoustic signal. Second, back vowel pairs were less accurately perceived than the front ones in the 4I-oddity test with a considerable difference. Third, in terms of voicing contrast following tense and lax vowels, a significant difference was only found in the 4I-oddity test. This finding verified that Korean speakers partially paid enhanced attention to vowel length when acquiring English high back tense and lax vowel contrast.

Perceptual vowel contrast reduction in Australian English /l/-final rimes

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, æɔl-æl/ 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.

Native non-prototypicality in vowel perception induces prominent neuromagnetic mismatch intensities in non-native speakers: a pilot study.

Neural mismatch response resulting from the difference between prediction and observation is related to change detection and discrimination. Robust neuromagnetic brain activity of auditory mismatch-related perception occurs in response to non-prototypical vowels inacross-category contrasts for first-language speakers. However, whether this non-prototypicality effect applies to within-category vowel perception remains to be elucidated. Here, healthy Japanese adults (n = 7) were subjected to magnetoencephalography (MEG) while watching a silent movie, and passively listened to synthesized English vowels /i/. We observed the source-level mismatch effect to the mid-high near-front vowel deviant [ɪ] with the most non-prototypical, unspecified feature in the participants' native language system. The mismatch effect recruited the left posterior superior temporal sulcus with a peak latency of 225ms post-stimulus onset. We further studied whether a longer F1 distance between vowel pairs would increase mismatch-activated intensities, however, we did not observe neuromagnetic changes when the prototypical anchor standard [i] was compared with three non-prototypical deviants differing in first resonance frequency (F1) values. Our results indicate that an F1 increase in within-category upper front vowel perception is a strong activator of mismatch responses measured by source-level activated intensities for non-native listeners.

Franklin D. Roosevelt and the American Theatre Standard: The low vowels

Franklin D. Roosevelt’s accent is often used as an illustration of the elite pronunciation heard among the north-eastern US upper classes until roughly the mid 20th century. Known under several names and often considered a mixture of British and American features, this variety is frequently identified with the American Theatre Standard, a norm popularized by acting schools in the early 20th century. Working on the assumption that Roosevelt is an exemplar of the north-eastern standard, the aim of the current study is a preliminary acoustic exploration of his accent with the aim of assessing the plausibility of such comparisons, focusing on the dress, trap, bath, start and lot vowels. Density plots created based on F1 and F2 measured in eight radio speeches were used to examine the relative position of these vowels in the vowel space. Linear mixed-effects regression was then used to model F1 and F2 in selected pairs of vowels to determine whether the differences along the two formant dimensions are significant. The results confirm a conclusion reached in an earlier auditory study (Brandenburg, Braden 1952) according to which Roosevelt’s bath was variable between [æ] and a lower and retracted [a], a vowel quality found in Eastern New England and in American Theatre Pronunciation. At the same time, a merged start/lot vowel in Roosevelt’s speech makes it unjustified to fully identify his accent with the latter variety.

Perceptuomotor compatibility effects in vowels: Effects of consonantal context and acoustic proximity of response and distractor.

In a cue-distractor task, speakers' response times (RTs) were found to speed up when they perceived a distractor syllable whose vowel was identical to the vowel in the syllable they were preparing to utter. At a more fine-grained level, subphonemic congruency between response and distractor-defined by higher number of shared phonological features or higher acoustic proximity-was also found to be predictive of RT modulations. Furthermore, the findings indicate that perception of vowel stimuli embedded in syllables gives rise to robust and more consistent perceptuomotor compatibility effects (compared to isolated vowels) across different response-distractor vowel pairs.

A Mispronunciation Detection Method of Confusing Vowel Pair for Chinese Students

This paper presents a discriminative features based mispronunciation detection method for confusing vowel pair /i/ vs /I/ that are frequently mispronounced by Chinese learners of English. Firstly, the mean of the 39-dimensional Mel Frequency Cepstral Coefficients (MFCC) feature vector over all the frames of the current phoneme segment is employed as features to characterize the phoneme. Secondly, many specific acoustic features that can effectively capture the crucial properties of the long and short vowels are extracted. Finally, the Support Vector Machine (SVM) classifier is used for discrimination between confusing vowels /i/ and /I/ by using the discriminative features extracted from each phoneme. The experimental results show that, the proposed method can produce higher accuracy than the traditional Automatic Speech Recognition (ASR) based methods. In addition, the combination of spectral features with specific acoustic features can achieve better performance than using individual features.

Modeling concurrent vowel identification for shorter durations

Behavioral studies on concurrent vowels with shorter duration (50 ms) show that overall identification scores across fundamental frequency (F0) differences are reduced when compared to longer duration (200 ms). In this current study, we investigated the effect of shorter durations on concurrent vowel scores using the temporal responses of an auditory-nerve model (Zilany et al., 2014) with a modified version of the Meddis and Hewitt (1992) F0-guided vowel segregation algorithm. The F0 representations of 50 ms vowel pairs were reduced but could not fully account for reduced identification, suggesting a limited ability to avail an F0-guided vowel segregation cue. Thus, by limiting only this cue in the segregation algorithm for 200 ms, the model was qualitatively successful in capturing lower scores across F0 differences for 50 ms. This differential ability to utilize an F0-guided segregation cue might contribute to a variable F0 benefit across normal-hearing listeners. The model also predicted an improvement in identification scores of the second vowel of the pair, when the duration was increased from 50 ms to 200 ms. These model predictions suggest that the inability to utilize an F0-guided segregation cue at shorter durations can account for reduced concurrent vowel identification scores across F0 differences.

Intelligibility of English Vowels Produced by Nigerian and Malaysian Speakers

The widespread use of the English language raises concerns about maintaining the mutual intelligibility across different nonnative English varieties. Some have viewed nonnative English varieties as distorted forms of English that cannot stand on their own that would cause the language to disintegrate into mutually unintelligible varieties. This study is an attempt to ascertain if there is mutual intelligibility between Nigerian and Malaysian English speakers, as there is little exploration of the intelligibility of African English varieties to Malaysians and vice versa. Forty Nigerians and 80 Malaysian undergraduate ESL students took part in a vowel discrimination task. The Nigerians listened to the words recorded by Malaysian speakers while the Malaysians listened to the words recorded by Nigerian speakers. Seven pairs of vowels were chosen as target vowel contrasts tested. Results showed that the Nigerians and Malaysians performed well in the discrimination task with performance above the guessing threshold for most of the selected pairs of vowel contrasts. Findings suggest that mutual intelligibility exists between the 2 recognized nonnative English varieties.

Perception of brazilian Portuguese open and close mid vowels by native Russian speakers

The perception of Brazilian Portuguese (BP) mid vowels is mainly investigated by foreign researchers who work with learners of Brazilian Portuguese, native speakers of English or Spanish. In Brazil, this field has been poorly explored. This work contributes to filling this gap by investigating the perception of two Brazilian Portuguese minimal vowel pairs in the group of 103 native Russian speakers and nine French speakers, most of them residing in Brazil. The test has been designed to evaluate the perception of the mid high and low front vowels [e] - [ε], and the mid high and low back vowels [o] - [ɔ]. The test is conducted online and includes 30 trials distributed in three types of tasks: image identification (8 trials), vowel identification (4) and word discrimination (18). It also contains a short sociolinguistic questionnaire. Our findings indicate that native Russian speakers do not differentiate the Brazilian Portuguese mid vowels very well: the mean percentage of the correct answers in the Russophone group was 68%, while in the French group it was 87% and in the Brazilian control group 99%. No correlation was found between the percentage of correct answers and residence time in Brazil or type of language instruction. As next steps, we plan to investigate the differentiation of the Brazilian Portuguese open and close mid vowels by Russophones at the level of production. We also intend to create a training corpus and develop strategies for perception training of the Brazilian Portuguese mid vowels, monitoring their efficiency at different time points.

An acoustic comparison of German tense and lax vowels produced by German native speakers and Mandarin Chinese learners.

This study analyzed the durational and spectral differences and their interaction in the production of seven German tense-lax vowel pairs between 30 German native speakers and 30 Mandarin learners of German. The results showed that Mandarin speakers differed significantly from the German speakers in producing the German tense-lax contrast. The general pattern was that Mandarin learners employed temporal features more strongly than spectral features to indicate the tense-lax contrast as compared to German speakers. The phonetic influences of the Mandarin language on the production of German tense and lax vowels are discussed.

Infants' use of isolated and combined temporal cues in speech sound segregation.

This paper investigates infants' and adults' use of envelope cues and combined onset asynchrony and envelope cues in the segregation of concurrent vowels. Listeners heard superimposed vowel pairs consisting of two different vowels spoken by a male and a female talker and were trained to respond to one specific target vowel, either the male /u:/ or male /i:/. Vowel detection was measured in three conditions. In the baseline condition the two superimposed vowels had similar amplitude envelopes and synchronous onset. In the envelope cue condition, the amplitude envelopes of the two vowels differed. In the combined cue condition, both the onset time and amplitude envelopes of the two vowels differed. Seven-month-old infants' concurrent vowel segregation improved both with envelope and with combined onset asynchrony and envelope cues to the same extent as adults'. A preliminary investigation with 3-month-old infants suggested that neither envelope cues nor combined asynchrony and envelope cues improved their ability to detect the target vowel. Taken together, these results suggest that envelope and combined onset-asynchrony cues are available to infants as they attempt to process competing speech sounds, at least after 7 months of age.

What vocabulary size tells us about pronunciation skills: Issues in assessing L2 learners

AbstractMeasures of second language (L2) learners’ vocabulary size have been shown to correlate with language proficiency in reading, writing and listening skills, and vocabulary tests are sometimes used for placement purposes. However, the relation between learners’ vocabulary knowledge and their speaking skills has been less thoroughly investigated, and even less so in terms of pronunciation. In this article, we compare vocabulary and pronunciation measures for 25 Italian instructed learners of L2 French. We measure their receptive (Dialang score) and productive (vocd-D, MTLD) vocabulary size, and calculate the following pronunciation indices: acoustic distance and overlap of realizations for selected L2 French vowel pairs, ratings of nasality forratings of foreign-accentedness, fluency metrics. We find that vocabulary measures show low to medium correlations with fluency metrics and ratings of foreign-accentedness, but not with vowel metrics. We then turn our attention to the impact of research methods on the study of vocabulary and pronunciation. More specifically, we discuss the possibility that these results are due to pitfalls in vocabulary and pronunciation indices, such as the failure of Dialang to take into account the effect of L1-L2 cognates, and the lack of measures for evaluating consonants, intonation and perception skills.

Phonetic realisations of Madurese vowels and their implications for the Madurese vowel system

It has been suggested that Madurese has eight surface vowels [a, ɛ, ə, ɔ, ɤ, i, ɨ, u], but there have been disagreements with regard to the number of its vowel phonemes. The disagreements arise partly because some scholars base their analyses of Madurese vowels on phonetic grounds while others base them on certain phonological analyses. Besides, some researchers do not consider native versus non-native Madurese words in their analyses. The paper addresses these problems by incorporating both phonetic and phonological analyses in order to provide a better description of Madurese vowels. To achieve this, we investigated the acoustic realisations of the eight surface vowels by looking at the first and second formant frequencies (F1 and F2) of the high and non-high vowel pairs (i ~ ɛ, ɨ ~ ə, ɤ ~ a, u ~ ɔ). Fifteen speakers of Madurese were recorded reading Madurese words put in a carrier phrase. All segmentations were done employing Praat, and F1 and F2 values were extracted using a Praat script. The data were assessed with a linear mixed-effects model accounting for variation due to both random and fixed factors. The results showed that all high and non-high vowel pairs significantly differed in their F1 values. However, the results for F2 values showed variations; only the pair [ɨ ~ ə] showed a significant difference at vowel onset and at vowel midpoint the pairs [i ~ ɛ] and [ɨ ~ ə] were significantly different. Furthermore, we also looked at the vowels [ɤ] and [ɨ] as well as [ɤ] and [ə] to see if they differed in their F1 and F2 values. Our results confirmed that at both vowel onset and midpoint, they were significantly different. The results were discussed employing phonological analysis and vowel dispersion theory. The result of the analyses suggests that Madurese should be best described as a language with a four-vowel system and further offers a solution to the disagreements on the number of vowel phonemes in Madurese

THE EFFECTS OF L1–L2 PHONOLOGICAL MAPPINGS ON L2 PHONOLOGICAL SENSITIVITY

AbstractThis study examines the effects of asymmetrical mappings of L2 sounds to L1 sounds on real-time processing of L2 phonology. L1-Korean participants completed a self-paced listening (SPL) task paired with a picture verification (PV) task, in which an English sentence was presented word by word along with a picture that matched or mismatched the sentence. In the critical region, an L2 vowel was deliberately replaced with the wrong vowel for two types of English vowel pairs: Type 1: English vowel pairs showing a one-to-one mapping to Korean counterparts (e.g., English: /i/ and /æ/ to Korean /i/ and /æ/, respectively); and Type 2: English vowel pairs showing a two-to-one mapping to a Korean counterpart (e.g., English /i/ and /ɪ/ to Korean /i/). We analyzed response times (RTs) and PV accuracy. Longer RTs were observed for Type 1 errors than Type 2 errors, indicating lower sensitivity to L2 vowels with two-to-one mapping to an L1 vowel. Also, PV accuracy was lower for the sentences containing Type 2 errors. These results suggest that asymmetrical L2-L1 sound mapping can affect learners’ processing of L2 phonological knowledge, which in turn can negatively affect their comprehension.

한국인 학습자의 영어 단모음 인지 연구

The purpose of this research is to corroborate PAM and PAM-L2 model including uncategorized phones. In order to accomplish this research purpose, the assimilation and discrimination experiments were conducted from 27 college students. The R statistics was used for data analysis. The findings of data analysis showed that 1) /ʌ/ was categorized as an uncategorized phone, 2) /ɛ-ӕ/ and /u-ʊ/ vowel pairs were categorized as SC, /i-ɪ/ as CG, /ʌ-ɔ/ as TC, and /ɑ-ʌ/ as UC-P assimilation type, 3) the degree of difficulties in discrimination was expected to be higher in the order of SC, UC-P=CG, and TC, & 4) the accuracy rate of discrimination was 59.2% & 66.7% for SC, 66.7% for UC-P, 77.8% for CG, and 96.3% for TC. The expectations of PAM and PAM-L2 model regarding the perceptual assimilation types and the degree of difficulties in discrimination were substantiated by the experiment results. Lastly, instructional implications for the foreign speech learning and suggestions for further study were also discussed.

Vowel and Sibilant Production in Noise: Effects of Noise Frequency and Phonological Similarity.

Purpose This study investigated vowel and sibilant productions in noise to determine whether responses to noise (a) are sensitive to the spectral characteristics of the noise signal and (b) are modulated by the contribution of vowel or sibilant contrasts to word discrimination. Method Vowel and sibilant productions were elicited during serial recall of three-word sequences that were produced in quiet or during exposure to speaker-specific noise signals. These signals either masked a speaker's productions of the sibilants /s/ and /ʃ/ or their productions of the vowels /a/ and /æ/. The contribution of the vowel and sibilant contrasts to word discrimination in a sequence was manipulated by varying the number of times that the target sibilant and vowel pairs occurred in the same word position in each sequence. Results Spectral noise effects were observed for both sibilants and vowels: Responses to noise were larger and/or involved to more acoustic features when the noise signal masked the acoustic characteristics of that phoneme class. Word discrimination effects were limited and consisted of only small increases in vowel duration. Interaction effects between noise and similarity indicated that the phonological similarity of sequences containing both sibilants and/or both vowels influenced articulation in ways not related to speech clarity. Conclusion The findings of this study indicate that sensorimotor control of speech exhibits some sensitivity to noise spectral characteristics. However, productions of sibilants and vowels were not sensitive to their importance in discriminating the words in a sequence. In addition, phonological similarity effects were observed that likely reflected processing demands related to the recall and sequencing of high-similarity words.

Perceptuomotor compatibility effects in vowels: Beyond phonemic identity

Perceptuomotor compatibility between phonemically identical spoken and perceived syllables has been found to speed up response times (RTs) in speech production tasks. However, research on compatibility effects between perceived and produced stimuli at the subphonemic level is limited. Using a cue–distractor task, we investigated the effects of phonemic and subphonemic congruency in pairs of vowels. On each trial, a visual cue prompted individuals to produce a response vowel, and after the visual cue appeared a distractor vowel was auditorily presented while speakers were planning to produce the response vowel. The results revealed effects on RTs due to phonemic congruency (same vs. different vowels) between the response and distractor vowels, which resemble effects previously seen for consonants. Beyond phonemic congruency, we assessed how RTs are modulated as a function of the degree of subphonemic similarity between the response and distractor vowels. Higher similarity between the response and distractor in terms of phonological distance—defined by number of mismatching phonological features—resulted in faster RTs. However, the exact patterns of RTs varied across response–distractor vowel pairs. We discuss how different assumptions about phonological feature representations may account for the different patterns observed in RTs across response–distractor pairs. Our findings on the effects of perceived stimuli on produced speech at a more detailed level of representation than phonemic identity necessitate a more direct and specific formulation of the perception–production link. Additionally, these results extend previously reported perceptuomotor interactions mainly involving consonants to vowels.

Acoustic Change Complex (ACC) using Speech and Non-Speech Stimuli in Normal Hearing Children

Abstract Background Cortical auditory evoked potentials (CAEPs) are brain responses evoked by sound and are processed in or near the auditory cortex. ACC is a cortical auditory evoked potential (P1-N1-P2) elicited by a change within an ongoing sound stimulus. Objective To reach the best stimuli that can elicit ACC and act as an objective tool for assessment of cortical auditory discrimination in normal hearing children. Patients and Methods The present study was originally designed to standardize ACC evoked response in 41 children aged from 2 to 10 years. The mean age in our study group was 6.2 years with no significant difference between males and females. Stimuli used in this study were specifically designed to be used by AEP equipment that is capable of uploading short duration stimuli (500 msec.), thus can be used in a regular AEP lab. ACC was elicited by three groups of stimuli. Gap-in-tones stimuli represent temporal change (6, 10, 30 and 50 msec. gap introduced to 1000 Hz tone separately), frequency pairs stimuli represent frequency change (2%, 4%, 10% and 25% change from base freq. 1000 Hz) and vowel pairs stimuli represent spectral change (/i-u/, /u-i/, /i-a/. /a-i/, /u-a/, /a-u/). ACC response parameters were compared when using the different stimuli as regards percent detectability, morphology, latency and amplitude. Results Gap-in-tones at 6 msec. and 4% frequency change could elicit ACC response in 100% of subjects. For spectral change, /u-i/ was the highest in eliciting ACC (78%) followed by /i-u/ (68.2%) then /a-i/ (58.5%). ACC had the same morphology of the onset response in the majority of subjects, with longer latency and smaller amplitude. ACC amplitude is a better indicator of cortical discrimination compared to latency because it is consistently affected by magnitude of change. Conclusion ACC is a good electrophysiological tool for cortical auditory discrimination for temporal, frequency and spectral change.