High Variability Phonetic Training Research Articles

High Variability [Pronunciation] Training (HVPT)

AbstractThis article is a critical research synthesis of 32 studies that used the High Variability Phonetic Training (HVPT) technique to teach learners to better perceive and produce L2 sounds. Taken together, the studies surveyed provide compelling evidence that HVPT is a very effective pronunciation training tool, and that resulting improvement is long-lasting. The analysis of this research also helps to explain why very few teachers have heard of this empirically-driven approach to pronunciation instruction: HVPT studies are largely published in technically oriented journals; few are accessible to language teachers. A variety of obstacles to the widespread use of HVPT are discussed, and some possible solutions are provided.

High variability phonetic training in adaptive adverse conditions is rapid, effective, and sustained.

This paper evaluates a novel high variability phonetic training paradigm that involves presenting spoken words in adverse conditions. The effectiveness, generalizability, and longevity of this high variability phonetic training in adverse conditions was evaluated using English phoneme contrasts in three experiments with Malaysian multilinguals. Adverse conditions were created by presenting spoken words against background multi-talker babble. In Experiment 1, the adverse condition level was set at a fixed level throughout the training and in Experiment 2 the adverse condition level was determined for each participant before training using an adaptive staircase procedure. To explore the effectiveness and sustainability of the training, phonemic discrimination ability was assessed before and immediately after training (Experiments 1 and 2) and 6 months after training (Experiment 3). Generalization of training was evaluated within and across phonemic contrasts using trained and untrained stimuli. Results revealed significant perceptual improvements after just three 20-minute training sessions and these improvements were maintained after 6 months. The training benefits also generalized from trained to untrained stimuli. Crucially, perceptual improvements were significantly larger when the adverse conditions were adapted before each training session than when it was set at a fixed level. As the training improvements observed here are markedly larger than those reported in the literature, this indicates that the individualized phonetic training regime in adaptive adverse conditions (HVPT-AAC) is highly effective at improving speech perception.

On the Role of Cognitive Abilities in Second Language Vowel Learning.

This study investigated the role of different cognitive abilities-inhibitory control, attention control, phonological short-term memory (PSTM), and acoustic short-term memory (AM)-in second language (L2) vowel learning. The participants were 40 Azerbaijani learners of Standard Southern British English. Their perception of L2 vowels was tested through a perceptual discrimination task before and after five sessions of high-variability phonetic training. Inhibitory control was significantly correlated with gains from training in the discrimination of L2 vowel pairs. However, there were no significant correlations between attention control, AM, PSTM, and gains from training. These findings suggest the potential role of inhibitory control in L2 phonological learning. We suggest that inhibitory control facilitates the processing of L2 sounds by allowing learners to ignore the interfering information from L1 during training, leading to better L2 segmental learning.

Using high variability phonetic training to train non-tonal listeners with no musical background to perceive lexical tones

Previous research has not extensively investigated whether High Variability Phonetic Training (HVPT) is effective in training listeners with no musical background and no prior experience with a tone language in their identification of non-native lexical tones. In this study, it was investigated whether HVPT is applicable to the acquisition of non-native tones by such listeners. Twenty-one speakers of American English were trained in eight sessions using the HVPT approach to identify Mandarin tones in monosyllabic words. Ten of the participants were exposed to words produced by multiple talkers (MT condition), and eleven participants were exposed to words produced by a single talker (ST condition). The listeners’ identification accuracy revealed an average 44% increase from the pretest to the posttest for the MT condition and an average 30% increase for the ST condition. The improvement also generalized to new monosyllabic words produced by a familiar talker and those produced by two unfamiliar talkers. The learning however did not generalize to novel disyllabic words produced either by a familiar talker or an unfamiliar talker. Comparisons between two groups further revealed that the improvement of the listeners in the MT condition was significantly higher than that of the listeners in the ST condition.

High Variability Phonetic Training as a Bridge From Research to Practice

High Variability Phonetic Training as a Bridge From Research to Practice

High or low? Comparing high and low-variability phonetic training in adult and child second language learners.

BackgroundHigh talker variability (i.e., multiple voices in the input) has been found effective in training nonnative phonetic contrasts in adults. A small number of studies suggest that children also benefit from high-variability phonetic training with some evidence that they show greater learning (more plasticity) than adults given matched input, although results are mixed. However, no study has directly compared the effectiveness of high versus low talker variability in children.MethodsNative Greek-speaking eight-year-olds (N = 52), and adults (N = 41) were exposed to the English /i/-/ɪ/ contrast in 10 training sessions through a computerized word-learning game. Pre- and post-training tests examined discrimination of the contrast as well as lexical learning. Participants were randomly assigned to high (four talkers) or low (one talker) variability training conditions.ResultsBoth age groups improved during training, and both improved more while trained with a single talker. Results of a three-interval oddity discrimination test did not show the predicted benefit of high-variability training in either age group. Instead, children showed an effect in the reverse direction—i.e., reliably greater improvements in discrimination following single talker training, even for untrained generalization items, although the result is qualified by (accidental) differences between participant groups at pre-test. Adults showed a numeric advantage for high-variability but were inconsistent with respect to voice and word novelty. In addition, no effect of variability was found for lexical learning. There was no evidence of greater plasticity for phonetic learning in child learners.DiscussionThis paper adds to the handful of studies demonstrating that, like adults, child learners can improve their discrimination of a phonetic contrast via computerized training. There was no evidence of a benefit of training with multiple talkers, either for discrimination or word learning. The results also do not support the findings of greater plasticity in child learners found in a previous paper (Giannakopoulou, Uther & Ylinen, 2013a). We discuss these results in terms of various differences between training and test tasks used in the current work compared with previous literature.

Ab initio perceptual learning of foreign language sounds: Spanish consonant acquisition by Chinese learners

High-variability phonetic training is effective in the acquisition of foreign language sounds. Previous studies have largely focused on small sets of contrasts, and have not controlled for the quantity of prior or simultaneous exposure to new sounds. The current study examined the effectiveness of phonetic training in full-inventory foreign language consonant acquisition by listeners with no previous exposure to the language. Chinese adult listeners underwent an intensive training programme, bracketed by tests that measured both assimilation of foreign sounds to native categories, and foreign category identification rates and confusions. Very rapid learning was evident in the results, with initial misidentification rates halving by the time of the mid-test, and continuing to fall in subsequent training sessions. Changes as a result of training in perceptual assimilation together with improved identifications and reduced response dispersion suggest an expansion of listeners’ native categories to accommodate the foreign sounds and an incipient process of foreign language category formation.

Effects of perceptual training on the perception of Korean boundary tones by Chinese learners

Previous studies have proven that High Variability Phonetic Training (HVPT) is an effective method for training non-native listeners to discriminate L2 phoneme contrasts or prosodic contrasts, such as Chinese tone and Japanese segment length. However, it still remains uninvestigated whether this training method can be successfully applied to the perceptual training of nondistinctive L2 intonation. This study aims to prove that the HVPT method is also effective in training Chinese learners of Korean to distinguish Korean boundary tones. Korean boundary tones have three important grammatical and pragmatic functions: distinction of declarative and interrogative sentences, distinction of wh- and yes-no questions, and distinction of ambiguous meanings of some terminal endings. Our experiment is designed to train Chinese learners to discriminate these three functions using the HVPT method. 40 Chinese learners participated in 10 online sessions. They were exposed to 276 sentences delivered by different speakers each session. The subjects showed significant improvements in discriminating all three intonational functions in the posttest. Lower proficiency learners showed greater improvements. A notable change occurred in the development of categorical perception. The category boundaries between declarative and interrogative sentences shifted closer to the native speakers’ after the training.

Research into practice: How research appears in pronunciation teaching materials

Research into pronunciation has often disregarded its potential to inform pedagogy. This is due partly to the historical development of pronunciation teaching and research, but its effect is that there is often a mismatch between research and teaching. This paper looks at four areas in which the (mis)match is imperfect but in which a greater recognition of research can lead to better teaching materials (high variability phonetic training, intonation, information structure, and setting priorities). Furthermore, two areas in which teaching materials are desperate for research to be carried out (connected speech and the primacy of suprasegmentals) will be discussed.

Second-Language Learners’ Identification of Target-Language Phonemes: A Short-Term Phonetic Training Study

Abstract: This study examined the effect of short-term high-variability phonetic training on the perception of English /b/, /v/, /d/, /ð/, /æ/, /#_x028C_#/, /i/, and /i/ by Catalan/Spanish bilinguals learning English as a foreign language. Sixteen English-major undergraduates were tested before and after undergoing a four-session perceptual training program involving a series of discrimination and identification tasks. Although some scores were already high at pre-test, there was improvement from pre-test to post-test, and this improvement generalized to novel words and a novel talker. An effect of word frequency was observed, but this effect was found to decrease after training. The results show that relatively advanced foreign-language learners in an instructional setting may improve in perception as a result of short-term high-variability phonetic training. The implications of these findings for the teaching of pronunciation are discussed.

Effect of phonetic training on the perception of English consonants by Greek speakers in quiet and noise conditions

The present study employed high-variability phonetic training (multiple words spoken by multiple talkers) to improve the identification of English consonants by native speakers of Greek. The trainees completed five sessions of identification training with feedback for seven English consonants (contrasting voiced vs. voiceless stops and alveolar vs. postalveolar fricatives) each consisting of 198 trials with a different English speaker in each session. Another group of Greek speakers served as controls, i.e., completed the pre/post test but received no training. Pre/post tests included English consonant identification in quiet and noise. In the noise condition, participants identified consonants in the presence of a competing English speaker at a signal-to-noise ratio of -2dB. The results showed that training significantly improved English consonant perception for the group that received training but not for the control group in both quiet and noise. The results add to the existing evidence that supports the effectiveness of the high-variability approach to second-language segmental training.

Improving L2 Listeners’ Perception of English Vowels: A Computer‐Mediated Approach

A high variability phonetic training technique was employed to train 26 Mandarin speakers to better perceive ten English vowels. In eight short training sessions, learners identified 200 English vowel tokens, produced in a post bilabial stop context by 20 native speakers. Learners’ ability to identify English vowels significantly improved in the training context and in one novel phonetic context. Training did not transfer to a third phonetic context. A delayed posttest indicated that improvement was maintained for one month after training was completed, although in the absence of training, no further improvement was found. Learners’ scalar judgments regarding the certainty of their choices on identification tests indicated a significant increase in confidence after training.

Auditory training for experienced and inexperienced second-language learners: Native French speakers learning English vowels

ABSTRACTThis study examined whether high-variability auditory training on natural speech can benefit experienced second-language English speakers who already are exposed to natural variability in their daily use of English. The subjects were native French speakers who had learned English in school; experienced listeners were tested in England and the less experienced listeners were tested in France. Both groups were given eight sessions of high-variability phonetic training for English vowels, and were given a battery of perception and production tests to evaluate their improvement. The results demonstrated that both groups learned to similar degrees, suggesting that training provides a type of learning that is distinct from that obtained in more naturalistic situations.

L2 speech learning in adulthood and phonological short-term memory

The aim of the present study is to extend research on individual differences in cognitive ability and second language acquisition by exploring the relationship between PSTM and L2 speech learning in advanced EFL learners. The participants (N=60) were a subset of a larger group of Catalan-Spanish bilingual EFL learners participating in 10 60-minute high-variability phonetic training sessions on the perception of the 11 British English monophthongs. Perceptual accuracy was assessed at pre- and post-test through categorization and discrimination tasks based on 5 monophthongal vowels (/i: ɪ æ ʌ ɑ:/). PSTM capacity measures were obtained at post-test using a SNWR task consisting of CVC Catalan nonwords on the basis of which participants were assigned to either low or high PSTM capacity groups The high PSTM group was found to obtain higher accuracy scores and greater perceptual accuracy gains than the low PSTM group. These results suggest that PSTM may play a role in L2 speech learning and may be involved in learners’ ability to successfully form phonetic categories for L2 sounds.

The effect of native vowel processing ability and frequency discrimination acuity on the phonetic training of English vowels for native speakers of Greek

The perception and production of nonnative phones in second language (L2) learners can be improved via auditory training, but L2 learning is often characterized by large differences in performance across individuals. This study examined whether success in learning L2 vowels, via five sessions of high-variability phonetic training, related to the learners' native (L1) vowel processing ability or their frequency discrimination acuity. A group of native speakers of Greek received training, while another completed the pre-/post-tests but without training. Pre-/post-tests assessed different aspects of their L2 and L1 vowel processing and frequency acuity. L2 and L1 vowel processing were assessed via: (a) Natural English (L2) vowel identification in quiet and in multi-talker babble, and natural Greek (L1) vowel identification in babble; (b) the categorization of synthetic English and Greek vowel continua; and (c) discrimination of the same continua. Frequency discrimination acuity was assessed for a nonspeech continuum. Frequency discrimination acuity was related to measures of both L1 and L2 vowel processing, a finding that favors an auditory processing over a speech-specific explanation for individual variability in L2 vowel learning. The most efficient frequency discriminators at pre-test were also the most accurate both in English vowel perception and production after training.

Adapting second language phonemic perception training to common instructional situations: Pitfalls and progress.

Adult language learners improve both perception and production of difficult target language phonemic contrasts through high variability phonetic training (HVPT) on minimal pairs. This training entails two alternative forced choice identifications with feedback of a corpus encompassing multiple talkers, tokens, and phonological contexts. This technique, refined most notably by Pisoni and colleagues [Bradlow et al. (1999)], has been little used in real pedagogical situations, due partly to inconvenient protocols (e.g., 1 h, 3 days per week, for 3 weeks) and partly to the difficulty of developing a robust presentation routine attractive to students. We have attacked these problems, and after two semesters of pilot work refining the training presentation (of English /r‐l/ to Japanese, Korean, and Chinese native learners), we expect this semester to have students who receive a full complement of training at ∼15 min, 2–3 days per week, throughout the term. Results will be presented and compared with previous research, and we will discuss some of the difficulties (technological, practical, and especially social) that were overcome for the sake naturalistic pedagogical application.

Training English vowels for French speakers with varying English experience

It is clear that high-variability phonetic training can improve speech perception for adult second-language learners, but it is uncertain what levels of processing are responsible for this change and whether this interacts with the previous experience of the learners. The present study investigated these issues by giving auditory training to French speakers with varying degrees of English experience. Listeners completed 8 sessions of high-variability identification training with clusters of minimal-pair words (e.g., sleet, slit, slight, slate) and a different speaker in each session. The pre/post tests evaluated changes in vowel perception using open-set identification in quiet and noise, a 3-interval category discrimination task, and a task in which individuals mapped their best exemplars for English vowels in a space that included formant movement and duration. The preliminary results suggest that French speakers improved substantially in their identification performance (about 20 percentage points), without having large changes in their ability to discriminate these categories. The results support a view that training improves the process of applying phonetic category knowledge, without changing the underlying categories themselves.

Training of English vowel perception by Finnish speakers to focus on spectral rather than durational cues

This study used the High-Variability Phonetic Training (HVPT) technique to train Finnish speakers to distinguish English vowels. It was found that Finnish speakers tend to use durational cues (which are phonemically relevant in their own language) to make a vowel category distinction rather than the relevant spectral cues. We used duration-modified stimuli with a HVPT program to 'force' the use of spectral cues. We focused on the /i/ (as in 'feet') vs /I/ (as in 'fit') vowel contrast and tested behavioural performance using a perceptual identification task. We also measured the Mismatch negativity (MMN) component of auditory event-related potential (ERP) before and after the training to look at changes in brain responses. The worst pre-test performance was for the 'modified duration' condition (i.e. where the learner had no choice but to rely on spectral cues). There were also asymmetries in vowel perception in both behavioural and MMN tasks, with the detection of /i/ being more difficult compared to the detection of /I/. Nevertheless, training did result in marked improvement of the most problematic contrasts for Finnish speakers.

Phonetic training with acoustic cue manipulations: A comparison of methods for teaching English /r/-/l/ to Japanese adults

Recent work [Iverson et al. (2003) Cognition, 87, B47-57] has suggested that Japanese adults have difficulty learning English /r/ and /l/ because they are overly sensitive to acoustic cues that are not reliable for /r/-/l/ categorization (e.g., F2 frequency). This study investigated whether cue weightings are altered by auditory training, and compared the effectiveness of different training techniques. Separate groups of subjects received High Variability Phonetic Training (natural words from multiple talkers), and 3 techniques in which the natural recordings were altered via signal processing (All Enhancement, with F3 contrast maximized and closure duration lengthened; Perceptual Fading, with F3 enhancement reduced during training; and Secondary Cue Variability, with variation in F2 and durations increased during training). The results demonstrated that all of the training techniques improved /r/-/l/ identification by Japanese listeners, but there were no differences between the techniques. Training also altered the use of secondary acoustic cues; listeners became biased to identify stimuli as English /l/ when the cues made them similar to the Japanese /r/ category, and reduced their use of secondary acoustic cues for stimuli that were dissimilar to Japanese /r/. The results suggest that both category assimilation and perceptual interference affect English /r/ and /l/ acquisition.

Auditory training with phonetic variability and acoustic enhancement: A comparison of /r/–/l/ training techniques for Japanese adults

High-variability phonetic training (HVPT) techniques have been successful for helping Japanese adults learn the English /r/–/l/ distinction. This success has been attributed to the fact that HVPT exposes listeners to naturalistic phonetic variability, from many talkers and phonetic contexts [e.g., Logan et al., J. Acoust. Soc. Am. 89, 874–886 (1991)]. The present investigation examined whether naturalistic phonetic variability is essential for effective training. HVPT (natural recordings from ten talkers) was compared with three conditions, in which signal processing was used to alter the phonetic variability of these natural recordings: all enhancement (F3 set to extreme values); perceptual fading (amount of F3 enhancement progressively decreased during training); and secondary cue variability (variability in F2 and duration cues progressively increased during training). The results thus far suggest that all of these training techniques were similarly effective, improving /r/–/l/ identification by an average of 15–20 percentage points for Japanese adults. It appears that the presence of naturalistic phonetic variability may not be critical to the effectiveness of HVPT. [Work supported by ESRC.]