Lexical Tone Production Research Articles

Musicians show enhanced perception, but not production, of native lexical tones.

Many studies have reported a musical advantage in perceiving lexical tones among non-native listeners, but it is unclear whether this advantage also applies to native listeners, who are likely to show ceiling-like performance and thus mask any potential musical advantage. The ongoing tone merging phenomenon in Hong Kong Cantonese provides a unique opportunity to investigate this as merging tone pairs are reported to be difficult to differentiate even among native listeners. In the present study, native Cantonese musicians and non-musicians were compared based on discrimination and identification of merging Cantonese tone pairs to determine whether a musical advantage in perception will be observed, and if so, whether this is seen on the phonetic and/or phonological level. The tonal space of the subjects' lexical tone production was also compared. Results indicated that the musicians outperformed the non-musicians on the two perceptual tasks, as indexed by a higher accuracy and faster reaction time, particularly on the most difficult tone pair. In the production task, however, there was no group difference in various indices of tonal space. Taken together, musical experience appears to facilitate native listeners' perception, but not production, of lexical tones, which partially supports a music-to-language transfer effect.

Production-perception relationship of Mandarin tones as revealed by critical perceptual cues.

The relationship of lexical tone production and perception has not been well studied. Using Mandarin tone, this research tests the hypothesis that a production-perception link is revealed by critical perceptual cues. The critical status of perceptual tonal cues was determined by perceptual cue weights, showing fundamental frequency (F0) contour as being more critical than height. Then, tone production features were examined for critical F0 contour (slope, curvature, turning-point location) and non-critical F0 height (mean, onset) cues. A production-perception correlation was found for F0 contour but not height cues, suggesting that critical perceptual cues dictate the relationship between production and perception.

중국어를 학습하는 한국어 모국어 화자의 중국어 성조 지각과 산출

Non-tonal language speakers may have difficulty learning second language lexical tones. In the present study, we explored this issue with Korean-speaking learners of Mandarin Chinese (i.e., non-tonal first language speakers) by examining their perception and production of Mandarin lexical tones. In the perception experiment, the Korean learners were asked to listen to the tone of each stimulus and assign it to one of four Mandarin lexical tones using the response keys; in the production experiment, the learners provided speech production data for the lexical tones and then their productions were identified by native listeners of Mandarin Chinese. Our results showed that the Korean learners of Mandarin Chinese had difficulty in perceptually distinguishing Tone 2 and Tone 3, with the most frequent production error being the mispronunciation of Tone 3 as Tone 2. We also investigated whether unfamiliar non-native phonemes (i.e., Chinese phonemes) that do not exist in the native language phonemic inventory (i.e., Korean) may hinder the processing of the non-native lexical tones. We found no evidence for such effects, neither for the perception nor for the production of the tones.

The Application Analysis of Neural Network Techniques on Lexical Tone Rehabilitation of Mandarin-Speaking Patients With Post-Stroke Dysarthria

The Objectives of this study are (1) to evaluate tone production in Mandarin-speaking patients with post-stroke dysarthria (PSD) using an artificial neural network (ANN), (2) to investigate the efficacy of recognition performance of the ANN model contrast to the human listeners and the convolutional neural network (CNN) model, and (3) to explore rehabilitation application of the artificial intelligence recognition for lexical tone production disorder with PSD. The subjects include two groups of native Mandarin speaking adults: 31 patients with PSD and 42 normal-speaking adults (NA) in a similar age range as controls. Each subject was recorded producing a list of 7 Mandarin monosyllables with 4 tones (i.e., a total of 28 tokens). The fundamental frequency (F0) of each monosyllable was extracted using auto-correlation algorithm. The ANN was trained with F0 data of the tone tokens from the NA, to generate the final model. The recognition rates of the human ears, ANN model, and CNN model were 87.78% ± 8.96% (mean ± SD), 89.11% ±11.80%, 65.91% ± 8.79% respectively for tone production of NA group; 70.28% ± 17.61%, 63.35% ± 17.40%, 34.71% ± 6.92% respectively for tone production of PSD group. For PSD group, there was significant correlation between the performance of the ANN model and human listeners (r = 0.826, P <; 0.001). However, the performance of CNN model was not correlated with that of the human ears (r = -0.108, P = 0.562). Thus, the experiments show that ANN is more objective and efficient, which could replace human listeners in the assessment of lexical tone production disorder in Mandarin-speaking patients with PSD. Furthermore, using ANN may reduce the heterogeneity of rehabilitation evaluation among different speech therapists and may give the feedback for achievement of rehabilitation treatment more accurately.

Processing of Acoustic Information in Lexical Tone Production and Perception by Pediatric Cochlear Implant Recipients.

Purpose: This study examined the utilization of multiple types of acoustic information in lexical tone production and perception by pediatric cochlear implant (CI) recipients who are native speakers of Mandarin Chinese.Methods: Lexical tones were recorded from CI recipients and their peers with normal hearing (NH). Each participant was asked to produce a disyllabic word, yan jing, with which the first syllable was pronounced as Tone 3 (a low dipping tone) while the second syllable was pronounced as Tone 1 (a high level tone, meaning “eyes”) or as Tone 4 (a high falling tone, meaning “eyeglasses”). In addition, a parametric manipulation in fundamental frequency (F0) and duration of Tones 1 and 4 used in a lexical tone recognition task in Peng et al. (2017) was adopted to evaluate the perceptual reliance on each dimension.Results: Mixed-effect analyses of duration, intensity, and F0 cues revealed that NH children focused exclusively on marking distinct F0 contours, while CI participants shortened Tone 4 or prolonged Tone 1 to enhance their contrast. In line with these production strategies, NH children relied primarily on F0 cues to identify the two tones, whereas CI children showed greater reliance on duration cues. Moreover, CI participants who placed greater perceptual weight on duration cues also tended to exhibit smaller changes in their F0 production.Conclusion: Pediatric CI recipients appear to contrast the secondary acoustic dimension (duration) in addition to F0 contours for both lexical tone production and perception. These findings suggest that perception and production strategies of lexical tones are well coupled in this pediatric CI population.

Acoustic-phonetic consequences of clear speech in Cantonese vowels and lexical tones

In adverse communicative contexts, speakers will modify their speech style to enhance intelligibility, which can involve a range of acoustic and articulatory adjustments. Prior work has focused on the influence of speaking style on spectral (e.g., vowel space expansion) and temporal distinctions (e.g., voice-onset time). Thus, this study investigated the extent to which such adjustments extend to the pitch dimension, namely lexical tone. Ten native Cantonese speakers were recorded producing five monosyllables with six Cantonese tones embedded in sentence contexts in both clear and conversational speaking styles. Acoustic analyses revealed that speakers produced two distinct styles, with longer vowel durations and greater vowel dispersion in clear relative to conversational speech. However, with regards to lexical tone production, the results indicated only a marginal re-adjustment of tones within the tone space as a result of clear speech. Specific contour tones, such as the low- and high-rising tones, saw increases in their F0 offset. However, mean F0, F0 range and tonal dispersion did not differ substantially between styles. These findings indicate that speakers maintain tonal stability across speaking styles, suggesting that, relative to segments, lexical tones may not be prioritized as phonological contrasts vital to enhance the overall intelligibility of the utterance.

Suprasegmental Features Are Not Acquired Early: Perception and Production of Monosyllabic Cantonese Lexical Tones in 4- to 6-Year-Old Preschool Children.

Previous studies reported that children acquire Cantonese tones before 3 years of age, supporting the assumption in models of phonological development that suprasegmental features are acquired rapidly and early in children. Yet, recent research found a large disparity in the age of Cantonese tone acquisition. This study investigated Cantonese tone development in 4- to 6-year-old children. Forty-eight 4- to 6-year-old Cantonese-speaking children and 28 mothers of the children labeled 30 pictures representing familiar words in the 6 tones in a picture-naming task and identified pictures representing words in different Cantonese tones in a picture-pointing task. To control for lexical biases in tone assessment, tone productions were low-pass filtered to eliminate lexical information. Five judges categorized the tones in filtered stimuli. Tone production accuracy, tone perception accuracy, and correlation between tone production and perception accuracy were examined. Children did not start to produce adultlike tones until 5 and 6 years of age. Four-year-olds produced none of the tones with adultlike accuracy. Five- and 6-year-olds attained adultlike productions in 2 (T5 and T6) to 3 (T4, T5, and T6) tones, respectively. Children made better progress in tone perception and achieved higher accuracy in perception than in production. However, children in all age groups perceived none of the tones as accurately as adults, except that T1 was perceived with adultlike accuracy by 6-year-olds. Only weak association was found between children's tone perception and production accuracy. Contradicting to the long-held assumption that children acquire lexical tone rapidly and early before the mastery of segmentals, this study found that 4- to 6-year-old children have not mastered the perception or production of the full set of Cantonese tones in familiar monosyllabic words. Larger development was found in children's tone perception than tone production. The higher tone perception accuracy but weak correlation between tone perception and production abilities in children suggested that tone perception accuracy is not sufficient for children's tone production accuracy. The findings have clinical and theoretical implications.

The perception of Mandarin lexical tones by native Korean speakers differing in their experience with Mandarin

While it is well established that non-native speakers differ from native speakers in their perception and/or production of Mandarin lexical tones, empirical studies focusing on non-native learners are still limited. The objective of this study is to add to the current understanding of lexical tone perception by comparing native speakers of standard Korean from the Seoul/Kyunggi area differing in Mandarin experience (NK1, NK2) with native speakers of Mandarin. NK1 ( n = 10) had no experience with Mandarin whereas NK2 ( n = 10) consisted of highly advanced learners of Mandarin. A group of 10 native Mandarin (NM) speakers was included as controls. Accuracy of perception of six tone pairs (T1–T2, T1–T3, T1–T4, T2–T3, T2–T4, T3–T4) was assessed in a four-alternative forced-choice discrimination test. As expected, the NK2 group with extensive Mandarin learning experience resembled the NM group to a greater extent than did the NK1 group. T2–T3 was the hardest pair for both NK groups, but NK2 had the largest advantage over NK1 for this pair. Apart from T2–T3 which is generally considered difficult, tone pairs involving T1 caused some misperception by the NK groups. This may be related to the difficulty with perceiving a level tone which shows the least fundamental frequency (F0) movement and possibly has limited perceptual salience.

Recent findings on children’s lexical tone development: Implications for models of speech development

Lexical tone is important for a majority of the world’s languages. Prior research consistently reported that children mastered lexical tone production between 1;6 to 2;6 of age, supporting the prevailing notion of theories of speech acquisition that children acquire supra-segmental features early and rapidly before mastering the full set of segmental features. However, intriguingly, studies that examined children’s Cantonese tone perception found that children failed to accurately identify Cantonese tones in monosyllabic words until after eight years old, five years after children’s full mastery of tone production at three years old, which questioned early acquisition of supra-segmental features and the widely accepted assumption in speech acquisition models that speech perception precedes speech production. Wong, Schwartz, and Jenkins (2005) started a series of studies using a new paradigm that controlled lexical expectation in tone rating to examine lexical tone development in children and reported strikingly different results. Monosyllabic and disyllabic tones produced by five and six years old Mandarin-speaking children growing up in the U.S. and in Taiwan and Cantonese-speaking children growing up in Hong Kong were not adult-like. Tone production development was slower than tone perception development. The findings shed new light on universal models and theories of speech acquisition.

Adaptation in Mandarin tone production with pitch-shifted auditory feedback: influence of tonal contrast requirements

ABSTRACTWe investigated Mandarin speakers’ control of lexical tone production with F0-perturbed auditory feedback. Subjects produced high level (T1), mid rising (T2), low dipping (T3), and high falling (T4) tones in conditions with (a) no perturbation, (b) T1 shifted down, (c) T1 shifted down and T3 shifted up, or (d) T1 shifted down and T3 shifted up but without producing other tones. Speakers and new subjects also completed a tone identification task with unaltered and F0-perturbed productions. With only T1 perturbed down, speakers adapted by raising F0 relative to no-perturbation. With simultaneous T1 down and T3 up perturbations, no T1 adaptation occurred, and T3 adaptation occurred only if T2 was also produced. Identification accuracy with stimuli representing adapted productions was comparable to baseline, but with simulated non-adapted productions it was reduced for T2 and T3. Thus, Mandarin speakers’ adaptation to F0 perturbations is linguistically constrained and serves to maintain tone contrast.

Understanding individual differences in perception and production of lexical tones through brain oscillations at theta and gamma frequency bands

Understanding individual differences in perception and production of lexical tones through brain oscillations at theta and gamma frequency bands

Phonetic complexity affects children's Mandarin tone production accuracy in disyllabic words: A perceptual study.

This is the first study to examine the effect of phonetic contexts on children’s lexical tone production. Mandarin tones in disyllabic words produced by forty-four 2- to 6-year-old children and twelve mothers were low-pass filtered to eliminate lexical information. Native Mandarin-speaking adults categorized the tones based on the pitch information in the filtered stimuli. All mothers’ tones were categorized with ceiling accuracy. Counter to the findings in most previous studies on children’s tone acquisition and the prevailing assumption in models of speech development that children acquire suprasegmental features much earlier than segmental features, this study found that children as old as six years of age have not mastered the production of Mandarin tones. Children’s tones were judged with significantly lower accuracy than mothers’ productions. Tone accuracy improved, while cross subject variability in tone accuracy decreased, with age. Children’s tone accuracy was affected by the articulatory complexity of phonetic contexts. Children made more errors in tone combinations with more complex fundamental frequency (F0) contours than tone sequences with simpler F0 changes. When producing disyllabic tone sequences with complex F0 contours, children tended to shift the F0 contour of the first tone to reduce the F0 change, resulting in more tone errors in the first syllable than in the second syllable and showing substantially more anticipatory coarticulation than adults. The results provide further evidence that acquisition of lexical tones is a protracted process in children. Tones produced accurately by children in one phonetic context may not be produced correctly in another phonetic context. Children demonstrate more anticipatory coarticulation in their disyllabic productions than adults, which may be attributed to children’s immature speech motor control in tone production, and is presumably a by-product of their inability to accomplish complex F0 changes within the syllable time-frame.

The application of artificial neural network on the assessment of lexical tone production of pediatric cochlear implant users

Objective: The present study was carried out to explore the tone production ability of the Mandarin-speaking children with cochlear implants (CI) by using an artificial neural network model and to examine the potential contributing factors underlining their tone production performance. The results of this study might provide useful guidelines for post-operative rehabilitation processes of pediatric CI users. Methods: Two hundred and seventy-eight prelingually deafened children who received unilateral CI participated in this study. As controls, 170 similarly-aged children with normal hearing (NH) were recruited. A total of 36 Chinese monosyllabic words were selected as the tone production targets. Vocal production samples were recorded and the fundamental frequency (F0) contour of each syllable was extracted using an auto-correlation algorithm followed by manual correction. An artificial neural network was created in MATLAB to classify the tone production. The relationships between tone production and several demographic factors were evaluated. Results: Pediatric CI users produced Mandarin tones much less accurately than did the NH children (58.8% vs. 91.5% correct). Tremendous variability in tone production performance existed among the CI children. Tones 2 and 3 were produced less accurately than tones 1 and 4 for both groups. For the CI group, all tones when in error tended to be judged as tone 1. The tone production accuracy was negatively correlated with age at implantation and positively correlated with CI use duration with correlation coefficients (r) of -0.215 (P=0.003) and 0.203 (P=0.005), respectively. Age was one of the determinants of tonal ability for NH children. Conclusions: For children with severe to profound hearing loss, early implantation and persistent use of CI are beneficial to their tone production development. Artificial neural network is a convenient and reliable assessment tool for the development of tonal ability of hearing-impaired children who are in the rehabilitation processes that focus on speech and language expression.

Congenital amusics use a secondary pitch mechanism to identify lexical tones.

Amusia is a pitch perception disorder associated with deficits in processing and production of both musical and lexical tones, which previous reports have suggested may be constrained to fine-grained pitch judgements. In the present study speakers of tone-languages, in which lexical tones are used to convey meaning, identified words present in chimera stimuli containing conflicting pitch-cues in the temporal fine-structure and temporal envelope, and which therefore conveyed two distinct utterances. Amusics were found to be more likely than controls to judge the word according to the envelope pitch-cues. This demonstrates that amusia is not associated with fine-grained pitch judgements alone, and is consistent with there being two distinct pitch mechanisms and with amusics having an atypical reliance on a secondary mechanism based upon envelope cues.

Lexical tone in Deori: loss, contrast and word based alignment

In this paper we investigate the existence of tones in Deori, a language which is historically known to have had tonal distinctions. In a study, 5 speakers were recorded for their production of potential lexical tones in a list of 34 words, and a list of 54 monosyllabic roots were recorded for a vowel experiment. We conducted an f0 analysis in order to examine the extent of ‘tonoexodus’ and loss of tonal properties in Deori. To the extent that experimental methods can be used to determine lexical tone, phonetic measurements of f0 and further statistical analysis reliably indicate the distribution of lexically distinct tones. The results show clear presence of tonally distinctive words but without any definitive tonal alignment. We consider the diachrony and synchronic analysis of this and conclude that the syllable is not the Tone Bearing Unit in the conventional sense in current Deori, and that there is no clinching evidence to suggest alignment and spreading of the lexically distinctive tone to the right edge. Given these results, we conclude that tone is spread in the entire word in Deori. We also note that Deori no longer exhibits the prototypical Tibeto-Burman sesquisyllabic pattern and has instead developed an iambic stress pattern.

Non-native perception and production of lexical tones before and after high-variability training

This study investigates non-native perception and production of lexical tones. 26 English speakers received 3 hours of high-variability AX training to perceive tonal contrasts in Cantonese. Half of them were trained with additional iconic tone marks (AV) and half of them were not (AO). Pre-test and post-test were conducted and both of them consisted of high-variability AXB followed by delayed repetition using the stimuli from AXB. Preliminary results showed that T2 (high-rising) vs. T5 (low-rising) and T3 (mid-level) vs. T6 (low-level) were the most difficult pairs in AXB, with about 70% correct for T2-T5 and slightly above chance performance for T3-T6 in post-test. AV listeners did not achieve significantly higher accuracy than AO listeners. In delayed repetition, both groups produced distinct contours for T2 and T5 and for T3 and T6 even in pre-test, which did not differ significantly from post-test. Exposure to pre-test AXB might have facilitated talker normalization and tone production in the delayed repetition task. In addition, AV subjects had slightly more semitone difference in the second half of rhyme (offset—50% of rhyme duration) for T2 in post-test than AO subjects, but this effect of iconic visual information is limited.

Developmental trends of perceiving happy voice in preverbal infants

Perception of emotional prosody is essential for children to identify emotions of communication partners from utterances. Newborns prefer listening to happy talks but children start to weight emotional prosody over lexical meanings to judge emotions in speech around middle childhood. Happy voice is expressed with higher fundamental frequency (F0) and F0 variations in syllables manifest lexical tones in Mandarin. Would lexical tones affect happy prosody perception development in preverbal infants? The goal of this study was to explore whether the ability of perceiving happy prosody varies with lexical tones. Mandarin-learning children master the production of Tone 2 earlier than Tone 3, and development trend of lexical tone production might reflect perceptual trends of lexical tones. Thirty-nine Mandarin-learning 7- and 11-month-old infants were tested with two prosody (happy vs. neutral prosody) contrasts in a speech discrimination task. For each contrast, speech stimuli were monosyllabic words /ji/, varied with emotional prosody. Tonal information (Tone 2 or Tone 3) varied between contrasts and remained the same within a contrast. Results showed that older infants were more accurate than younger infants to distinguish happy prosody and the pitch contours of lexical tones did not greatly shift the developmental trend.

The Neural Substrates Underlying the Implementation of Phonological Rule in Lexical Tone Production: An fMRI Study of the Tone 3 Sandhi Phenomenon in Mandarin Chinese.

This study examined the neural substrates underlying the implementation of phonological rule in lexical tone by the Tone 3 sandhi phenomenon in Mandarin Chinese. Tone 3 sandhi is traditionally described as the substitution of Tone 3 with Tone 2 when followed by another Tone 3 (33 →23) during speech production. Tone 3 sandhi enables the examination of tone processing in the phonological level with the least involvement of segments. Using the fMRI technique, we measured brain activations corresponding to the monosyllable and disyllable sequences of the four Chinese lexical tones, while manipulating the requirement on overt oral response. The application of Tone 3 sandhi to disyllable sequence of Tone 3 was confirmed by our behavioral results. Larger brain responses to overtly produced disyllable Tone 3 (33 > 11, 22, and 44) were found in right posterior IFG by both whole-brain and ROI analyses. We suggest that the right IFG was responsible for the processing of Tone 3 sandhi. Intense temporo-frontal interaction is needed in speech production for self-monitoring. The involvement of the right IFG in tone production might result from its interaction with the right auditory cortex, which is known to specialize in pitch. Future studies using tools with better temporal resolutions are needed to illuminate the dynamic interaction between the right inferior frontal regions and the left-lateralized language network in tone languages.

The effects of language learning and vocal training on sensorimotor control of lexical tone

To perceive and produce Mandarin, adult second language (L2) learners need to learn to discriminate lexical pitch variations and develop the new sensorimotor skills needed to produce the lexical tones. In this paper, we investigated whether auditory discrimination and sensorimotor integration differ with Mandarin (tonal) language experience in the context of tonal language syllables and simple sustained vowels. We tested four distinct groups: native Mandarin speakers, Mandarin L2 adults, trained vocalists, and naïve adults (those with no tonal language exposure). Auditory discrimination was measured using two perceptual tasks, musical tone discrimination and Mandarin tone discrimination, the results of which were compared across the four groups. Group differences in sensorimotor integration related to lexical tone production were examined with a pitch-shift paradigm that assessed rapid motor responses to unexpected pitch perturbations. Mandarin speakers performed significantly better on Mandarin tone discrimination compared to the other three groups. Mandarin speakers also showed more attenuation of pitch-shift response amplitude (better vocal pitch control) during production of both the sustained vowel and Mandarin tones, especially compared to naïve speakers. These findings suggest that Mandarin speakers have more robust pitch control over self-produced vocalizations and are thus less affected by auditory feedback perturbations. This effect was particularly evident in response to the Mandarin high level lexical tone, for which the pitch-shift compensation patterns (with apparent attenuation in Mandarin speakers only) differed qualitatively from those of sustained vowels (with clear compensation in all groups), the rising tone (with apparent attenuation in all groups but naïve speakers), and the falling tone (with apparent attenuation in all groups). Trained vocalists also appear to rely more than naïve speakers on internal models when regulating voice F0 in the nonlinguistic domain (sustained vowel), but not in the linguistic domain (Mandarin tone). Native Mandarin speakers demonstrate robust internal models for lexical tone in both perception and production; this underscores the importance of developmental language experience but also provides evidence for the declination of the high level lexical tone which requires a mastery of tonal languages.

Implicit target substitution and sequencing for lexical tone production in Chinese: an FMRI study.

In this study, we examine the neural substrates underlying Tone 3 sandhi and tone sequencing in Mandarin Chinese using fMRI. Tone 3 sandhi is traditionally described as the substitution of Tone 3 with Tone 2 when followed by another Tone 3 (i.e., 33→23). According to current speech production models, target substitution is expected to engage the posterior inferior frontal gyrus. Since Tone 3 sandhi is, to some extent, independent of segments, which makes it more similar to singing, right-lateralized activation in this region was predicted. As for tone sequencing, based on studies in sequencing, we expected the involvement of the supplementary motor area. In the experiments, participants were asked to produce twelve four-syllable sequences with the same tone assignment (the repeated sequences) or a different tone assignment (the mixed sequences). We found right-lateralized posterior inferior frontal gyrus activation for the sequence 3333 (Tone 3 sandhi) and left-lateralized activation in the supplementary motor area for the mixed sequences (tone sequencing). We proposed that tones and segments could be processed in parallel in the left and right hemispheres, but their integration, or the product of their integration, is hosted in the left hemisphere.