Cantonese Tones Research Articles

Examining the cognitive and perceptual perspectives of music-to-language transfer: A study of Cantonese–English bilingual children

Motivated by theories of music-to-language transfer, we investigated whether and how musicianship benefits phonological and lexical prosodic awareness in first language (L1) Cantonese and second language (L2) English. We assessed 86 Cantonese–English bilingual children on rhythmic sensitivity, pitch sensitivity, nonverbal intelligence, inhibitory control, working memory, Cantonese phonological awareness, Cantonese tone awareness, English phonological awareness, and English stress awareness. Based on their prior music learning experience, we classified the children as musicians and non-musicians. The musicians performed better than the non-musicians on Cantonese phonological awareness, Cantonese tone awareness, and English phonological awareness. In addition, the musicians had superior pitch sensitivity, nonverbal intelligence, inhibitory control, and working memory than the non-musicians. For Cantonese and English phonological awareness, neither cognitive abilities nor pitch and rhythmic sensitivities turned out to be a unique predictor. However, working memory uniquely predicted Cantonese tone awareness, with age, rhythmic sensitivity, and pitch sensitivity controlled. From a theoretical perspective, our findings on Cantonese tone awareness favors the cognitive perspective of music-to-language transfer, in which working memory enhancement could explain the musicians’ superior performance in Cantonese tone awareness. However, our findings on phonological awareness do not favor the cognitive perspective, nor do they favor the perceptual perspective, in which enhanced rhythmic and pitch sensitivities could explain musicians’ advantage.

Acoustic Analyses of Tone Productions in Sequencing Contexts Among Cantonese-Speaking Preschool Children With and Without Childhood Apraxia of Speech.

Pitch variations (tone productions) have been reported as a measure to differentiate Cantonese-speaking children with and without childhood apraxia of speech (CAS). This study aims to examine fundamental frequency (F0) changes within syllables and the effects of syllable structure, lexical status, and syllable positions on F0 in Cantonese-speaking preschool children with and without CAS. Six children with CAS, six children with non-CAS speech sound disorder plus language disorder (S&LD), 22 children with speech sound disorder only (SSD), and 63 children with typical speech-language development (TD) performed the tone sequencing task (TST). Growth curve analysis was employed to analyze and compare the F0 values within syllables with three Cantonese tones (high level, high rising, and low falling). The analysis considered the effects of syllable structure (vowel and consonant-vowel), lexical status (word and nonword), and syllable position (initial, medial, and final) on F0, as well as comparisons within and between groups. Within each group, the effects of syllable structure and position on F0 values were found with different patterns. Between-group comparisons showed that the CAS group had reduced F0 contrasts. The CAS group could be differentiated from the control groups based on interactions of F0 with syllable structure and position, but not lexical status. The dissimilarity of F0 values detected between the CAS and SSD/TD groups was more prominent than that observed between the CAS and S&LD groups. This study demonstrated that Cantonese-speaking children with CAS had difficulty in varying F0 within syllables as compared to those without CAS, suggesting pitch variation difficulty and language-specific impairment profiles in CAS. Future investigations of objective measures for identifying Cantonese speakers with CAS and cross-linguistic investigations using growth curve analysis and the TST are suggested.

A psychological study of Cantonese tone confusion based on computer experimental data

The paper is based on computer experimental data and aims at investigating the pronunciation of Cantonese tones by 40 participants in Guancheng. Accordingly, three methods, namely, the preparatory pronunciation, pronunciation experiment and perception experiment were applied to examine the tones. The methods correspond to three levels of psychological identification. As the result, confusions of Cantonese tones were summarized and the related reasons were analyzed. The psychological identification of different levels was found to show different trends in the confusion of the tone. Moreover, according to the preparatory experiment, as shallow level psychological identity, the similarity of the adjustment and modulation can be argued to be the internal reason of the confusion. As the medium level psychological identity, the pronunciation experiment suggested that the weakening of socialized pronunciation can lead to tone confusion. Finally, as the deep psychological identity, the experimental study of perception demonstrated the perceptual similarity as the direct psychological motivation of the confusion..

The effect of second-language learning experience on Korean listeners’ use of pitch cues in the perception of Cantonese tones

Past studies have found that the linguistic experience of previously-acquired languages, such as one’s native-language (L1) and second-language (L2) learning experience, modulates the perception of novel sounds from a third language (L3). Lexical tone in L3 is a good case for testing the influence of L1 or L2, as listeners with varying language backgrounds may use different pitch cues (pitch contour or height) in tone perception. The present study focuses on L2 learners of Mandarin whose L1 variety is either Seoul Korean (SK), a non-tonal stressless language, or Gyeongsang Korean (GK), a tonal pitch-accent language. Intermediate-to-advanced SK-speaking and GK-speaking L2 learners of Mandarin were recruited as target groups, and naive listeners of respective L1 varieties were recruited as control groups. The participants completed an AX forced-choice tone discrimination task. Four Cantonese tones, one rising tone and three level tones, were used. Contour–level and level–level tonal contrasts were target tone pairs, allowing for testing the primary use of pitch contour and pitch height, respectively. The results showed that the two groups of naive listeners had greater accuracy in discriminating level–level than contour–level tonal contrasts. In contrast, L2 learners, independent of their L1 varieties, showed higher accuracy in discriminating contour–level than level–level tonal contrasts. The L2 learners’ perceptual pattern is consistent with Mandarin listeners, as reported in previous work. Taken together, the findings provide evidence for a possible developmental change in which Korean-speaking L2 learners might have a perceptual cue shift from pitch height to pitch contour through their L2 experience in Mandarin. The findings about the role of L2 proficiency in Mandarin further supported the effect of L2 experience on learners’ increased use of pitch contour.

Prior knowledge benefits older adults' tonal consolidation through talker generalization

Recent research indicated that post-training sleep facilitates memory consolidation and talker generalization in young adults' tone learning. For instance, a nap study showed the newly learned tonal contrast that relates to prior knowledge consolidated more rapidly than that does not after daytime naps. Notably, older adults' declarative memory consolidation is impaired with age-related changes in sleep architecture. The current study examines whether prior (contour-tone) knowledge benefits Mandarin-speaking older adults' Cantonese tone learning. Mandarin employs pitch contours (falling versus rising) to cue tones in signaling word identity. Besides pitch contours, Cantonese also utilizes pitch heights (higher versus lower) in level tones to encode word meanings. In the pilot phase (60 Mandarin-speaking older adults will be recruited with data collection ongoing), participants were trained to learn Cantonese contour-level and level-level contrasts in the evening or the morning. A novel word-object identification task was used in the training, followed by three tone identification tasks: a posttest immediately after training, a 12-h delayed posttest (a trained talker), and another delayed posttest (a novel talker). Aligned with the nap study, preliminary results suggested overnight sleep might enhance seniors' tone-related memory by promoting generalization across talkers in learning contour-level contrast owing to their prior contour-tone knowledge.

Phonetic adaptation in conversation: The case of Cantonese tone merging

Phonetic adaptation occurs when one interlocutor adjusts their speech to converge to or diverge from that of their conversation partner to enhance intelligibility. While most research investigates segmental adaptations, our study focuses on suprasegmentals, specifically Cantonese tone merging. Some Cantonese speakers (“mergers”) are found to merge certain lexical tones (e.g., mid-level Tone3 and low-level Tone6), which may cause confusions when interacting with non-merger speakers. Previous research has shown that a merger may unmerge a level tone pair (Tone3/Tone6) when shadowing a non-merger. However, still unclear is whether such changes result from automatic acoustic mimicking or reflect goal-oriented adaptations for intelligibility benefits. This study uses an unscripted conversation task involving a merger and a non-merger playing a video game, where productions of merged tones may cause confusions, thus motivating goal-oriented adaptations. Initial acoustic analyses focus on average F0 and F0 taken at 10 points along the contour in target Tone3 and Tone6 productions by mergers. Differences in these values for Tone3 versus Tone6 provide evidence that a merger is unmerging the tone pair. Preliminary results show increasing unmerging trends as the task progresses, suggesting progressive alignment toward a non-merger’s productions for intelligibility gains.

Pitch Variation Skills in Cantonese Speakers With Apraxia of Speech After Stroke: Preliminary Findings of Acoustic Analyses.

Literature on apraxia of speech (AOS) in Chinese speakers is sparse compared to the English literature. This study aims to examine the pitch variation skills of Cantonese adults with AOS poststroke in terms of perceptual tone accuracy, acoustic fundamental frequency (fo) changes, and repetition durations on items with different syllable structures, lexical status, and tone syllables in various positions in a sequencing context. Six Cantonese adults with AOS poststroke (AOS group), six adults without AOS poststroke (nAOS group), and six healthy controls (HC group) performed the tone sequencing task (TST), which was adapted from oral diadochokinetic tasks, with three different tone syllables. Tone accuracy, fo values across 10 time points, and acoustic repetition durations were compared within and between the groups. The AOS group produced significantly lower tone accuracy and different fo changes on the three Cantonese tone syllables compared with the control groups and significantly longer repetition durations than the HC group. The AOS group showed more difficulty with the tone syllables with the consonant-vowel structure, while a priming effect was observed on the T2 (high-rising) syllables with lexical meanings. A unique lowering of fo in the final syllable of the trisyllabic items was observed only in the AOS group. The AOS group showed degraded pitch variation skills. The effects of the three linguistic elements were discussed. Future investigations are called for to adapt the TST in other tonal languages to determine if degraded pitch variation skills are present in other tonal language speakers with AOS.

The development of tone discrimination in infancy: Evidence from a cross-linguistic, multi-lab report.

We report the findings of a multi-language and multi-lab investigation of young infants' ability to discriminate lexical tones as a function of their native language, age and language experience, as well as of tone properties. Given the high prevalence of lexical tones across human languages, understanding lexical tone acquisition is fundamental for comprehensive theories of language learning. While there are some similarities between the developmental course of lexical tone perception and that of vowels and consonants, findings for lexical tones tend to vary greatly across different laboratories. To reconcile these differences and to assess the developmental trajectory of native and non-native perception of tone contrasts, this study employed a single experimental paradigm with the same two pairs of Cantonese tone contrasts (perceptually similar vs. distinct) across 13 laboratories in Asia-Pacific, Europe and North-America testing 5-, 10- and 17-month-old monolingual (tone, pitch-accent, non-tone) and bilingual (tone/non-tone, non-tone/non-tone) infants. Across the age range and language backgrounds, infants who were not exposed to Cantonese showed robust discrimination of the two non-native lexical tone contrasts. Contrary to this overall finding, the statistical model assessing native discrimination by Cantonese-learning infants failed to yield significant effects. These findings indicate that lexical tone sensitivity is maintained from 5 to 17 months in infants acquiring tone and non-tone languages, challenging the generalisability of the existing theoretical accounts of perceptual narrowing in the first months of life. RESEARCH HIGHLIGHTS: This is a multi-language and multi-lab investigation of young infants' ability to discriminate lexical tones. This study included data from 13 laboratories testing 5-, 10-, and 17-month-old monolingual (tone, pitch-accent, non-tone) and bilingual (tone/non-tone, non-tone/non-tone) infants. Overall, infants discriminated a perceptually similar and a distinct non-native tone contrast, although there was no evidence of a native tone-language advantage in discrimination. These results demonstrate maintenance of tone discrimination throughout development.

Neural encoding of Cantonese and Vietnamese tones

The present pilot study investigates the neural encoding of lexical tones in Cantonese and Vietnamese. Better encoding of tones was found in native than non-native tone language speakers in previous research, with fewer studies examining language-specific effects. An identical equipment setup was used to measure neural responses to three lexical tones in Hong Kong (HK) (by Cantonese speakers) and Ho Chi Minh City (by Vietnamese speakers). The three tones were the high rising (35), dipping (214), and low falling (21) tones, of which the 21 and 214 tones were unique to Cantonese and Vietnamese respectively. If better tone encoding is language-specific, Vietnamese and Cantonese adult speakers are expected to show enhanced encoding of these tones. Across the majority of temporal and spectral measures, we did not find significant group differences across tonal categories, suggesting that enhancement of neural encoding found in native speakers was likely to be language general. If confirmed with a larger sample size, these findings may suggest that clinical tools utilizing speech stimuli for the assessment of spoken language processing and its related functions may not necessarily require customization for a specific language. [Work supported by ITF in HK.]

The more the better? Effects of L1 tonal density and typology on the perception of non-native tones.

This study investigates the effects of L1 tonal density and typology on naïve listeners' perception of L2 Cantonese tones and pitch-equivalent pure tones. Native speakers of two canonical tone languages (Vietnamese and Mandarin) and a pitch-accent language (Japanese) with varying degrees of tonal density were recruited as listeners in a discrimination task followed by a perceptual assimilation task. Results implied that Mandarin listeners with a sparser tone inventory exhibited significantly better performance than Vietnamese listeners, suggesting that denser tonality in L1 did not facilitate or even interfere with L2 tone perception. Furthermore, both groups of canonical tone listeners processed pitch contours in a domain-general manner, with comparable performance in the perception of lexical tones and pure tones. However, Japanese listeners of the pitch-accent language perceived pure tones better than lexical tones, showing a domain-specific mechanism. These findings suggest that both L1 tonal density and typology may modulate the perception of non-native tones.

Perceptual effects of lexical competition on Cantonese tone categories

Listeners use lexical information and the speech signal to categorize sounds and recognize words despite substantial acoustic-phonetic variation in natural speech. In diachronic mergers, where systematic variation acts to neutralize lexical contrasts, the role of the lexicon becomes less clear. We examined how lexical competition structures phonetic variability of (merging) lexical tone categories in Cantonese using three experiments. Listeners categorized tokens from lexical tone continua generated from minimal pairs (Experiment 1: Word identification) and categorized tokens from tone continua generated from word-nonword pairs (Experiment 2: Lexical decision). The presence of a lexical competitor at both continuum endpoints in Experiment 1 maintained more discrete categorization functions for non-merging tone pairs than in Experiment 2 where only one endpoint was a word. In the merging tone pairs, categorization was less discrete and the effect of lexical competition was different. Exploratory data from a goodness rating task, Experiment 3, suggest that lexical competition affects internal category structure for merging tones, but not non-merging tones. Overall, these data provide evidence that tone mergers affect phonetic category boundaries and internal category structure in the lexicon, and that, for non-merging tones, the range of acceptable phonetic variation is constrained by the presence of a lexical competitor.

Tonal context influences tone-duration interaction: Evidence from Cantonese.

Phonetic typological studies suggest that syllable duration is inversely correlated with the accompanying tone's approximate average f0, and tones with dynamic f0 movement tend to be in longer syllables rather than shorter ones. Systematic instrumental investigations on tone-duration interaction remain scant, however; existing studies might be confounded as tonal context may impact duration realization due to phonetic constraints on tonal movement. This study investigates the effect of tonal environment on the durational realization of tones in Cantonese, showing that tone-dependent duration variation is governed by the tonal context. Implications of these findings for existing phonetic typology concerning tone-duration interaction are discussed.

Noise-induced change of tone dispersion in Cantonese speech

Noise effect on speaking non-tonal languages is reported on acoustic correlates including increased intensity, enlarged vowel space and raised fundamental frequency. Adverse influence may also be present in realization of tones, which however remains under-explored. Tone-space size and the according tone dispersion offer key indicators to the nature of a tonal system. The present study investigates whether and how Cantonese tones are modified in speaking under noise. Adult native speakers of Cantonese read tri-syllabic words embedded in carrier sentences in quiet and under multi-talker babbles. The speech materials cover six tones (T55, T25, T33, T21, T23, T22) and are balanced between high-low and low-high tone combinations to avoid biased articulatory effects. Results confirm Lombard speech effect in Cantonese speaking. Moreover, under the noise condition, tone spaces of all six tones are enlarged and tones are more dispersed, especially in realization of T55 and T21 that mark the upper and lower ranges of the tonal space. Changes in tone production by female speakers are more significant than those in male speech. This study provides new evidence of phonetic accommodation under noise and in particular noise effects on sizes of tone space, which is not found in the production of monosyllabic words in Cantonese. Our speakers may have used labored speech production to compensate for signal degradation under babble noise, leading to higher dispersion of tones than clear speech in quiet.

Why Aren't All Cantonese Tones Equally Confusing to English Listeners?

English listeners often struggle to perceive tones, but some are easier than others. This study examined these phenomena grounded in the feature weighing perspective (FWP) and the Perceptual Assimilation Model for Suprasegmentals (PAM-S). Forty-seven English and Cantonese listeners completed 4,212 trials of Cantonese tone discrimination and sequence recall tasks. The English listeners showed asymmetrical perceptual patterns of discrimination but not sequence recall. Specifically, these English listeners discriminated T1-T5, T3-T5, and T4-T5 more accurately than T1-T4, T3-T4, and T1-T3. However, they recalled the contour tone and level tone sequences with similar accuracies. Results of the discrimination task aligned with the predictions of PAM-S but not FWP. However, results of the sequence recall task did not support PAM-S. Together, these results suggest that PAM-S only applies to simple discrimination, not abstract phonological processing with a high memory load.

The ability to use contextual cues to achieve phonological constancy emerges by 14 months.

The ability to map similar sounding words to different meanings alone is far from enough for successful speech processing. To overcome variability in the speech signal, young learners must also recognize words across surface variations. Previous studies have shown that infants at 14 months are able to use variations in word-internal cues (i.e., acoustic cues within the target word) to form phonological categories and to learn words. The present study takes into consideration the fact that talker variability can easily lead to acoustic overlap between phonological categories, in which case reliance on word-external cues (i.e., acoustic cues in the context preceding and/or following the target word, also referred to as contextual cues) as a frame of reference is obligatory for successful talker adaptation. In a series of experiments, the present study examines when infants are able to use word-external cues to tune to different talkers for the benefit of word learning. Cantonese-learning 14-month-old, 18-month-old, and 24-month-old infants (N = 258) were tested on the associative learning of Cantonese Tone 1-Tone 3 contrast. Results showed that talker variability that yielded acoustic overlap between the two tonal categories compromised infants' ability to map the contrast onto word meanings. However, when given speaker-matched contextual cues, infants as young as 14 months of age demonstrated a certain degree of talker adaptation which may have subserved their use of phonetic details in novel word learning. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Phonetic and Lexical Encoding of Tone in Cantonese Heritage Speakers.

Heritage speakers contend with at least two languages: the less dominant first language (L1), that is, the heritage language, and the more dominant second language (L2). In some cases, their L1 and L2 bear striking phonological differences. In the current study, we investigate Toronto-born Cantonese heritage speakers and their maintenance of Cantonese lexical tone, a linguistic feature that is absent from English, the more dominant L2. Across two experiments, Cantonese heritage speakers were tested on their phonetic/phonological and lexical encoding of tone in Cantonese. Experiment 1 was an AX discrimination task with varying inter-stimulus intervals (ISIs), which revealed that heritage speakers discriminated tone pairs with disparate pitch contours better than those with shared pitch contours. Experiment 2 was a medium-term repetition priming experiment, designed to extend the findings of Experiment 1 by examining tone representations at the lexical level. We observed a positive correlation between English dominance and priming in tone minimal pairs that shared contours. Thus, while increased English dominance does not affect heritage speakers' phonological-level representations, tasks that require lexical access suggest that heritage Cantonese speakers may not robustly and fully distinctively encode Cantonese tone in lexical memory.

The effect of simultaneous exposure on the attention selection and integration of segments and lexical tones by Urdu-Cantonese bilingual speakers.

In the perceptual learning of lexical tones, an automatic and robust attention-to-phonology system enables native tonal listeners to adapt to acoustically non-optimal speech, such as phonetic conflicts in daily communications. Previous tone research reveals that non-native listeners who do not linguistically employ lexical tones in their mother tongue may find it challenging to attend to the tonal dimension or integrate it with the segmental features. However, it is unknown whether the attentional interference initially caused by a maternal attentional system would continue influencing the non-optimal tone perception for simultaneous bilingual teenagers. From an endpoint in the age of language acquisition, we investigate whether the tone-specific attention mechanism developed by the Urdu-Cantonese simultaneous bilinguals is automatic enough to assist them in adapting to a phonetically-conflicting environment. Three groups of teenagers engaged in a four-condition ABX task: Urdu-Cantonese simultaneous bilinguals, Cantonese native listeners, and Urdu-speaking, late learners of Cantonese. The results showed that although the simultaneous bilinguals could phonologically process Cantonese tones in a Cantonese-like way under a conflict-free listening condition, they still failed in adapting to the phonetic conflicts, especially the segment-induced ones. It thus demonstrated that the simultaneous exposure and years of regular education in Hong Kong local schools still could not automatically guarantee simultaneous bilingual processing of Cantonese tones. In interpreting the findings, it hypothesized that, except for simultaneous exposure, the development of a tone-specific attention mechanism is also likely to be L1-inhibitory, tone experience-driven, and language-specific for simultaneous bilinguals.

The effects of alphabetic literacy, linguistic-processing demand and tone type on the dichotic listening of lexical tones.

Brain lateralization of lexical tone processing remains a matter of debate. In this study we used a dichotic listening paradigm to examine the influences of the knowledge of Jyutping (a romanization writing system which provides explicit Cantonese tone markers), linguistic-processing demand and tone type on the ear preference pattern of native tone processing in Hong Kong Cantonese speakers. While participants with little knowledge of Jyutping showed a previously reported left-ear advantage (LEA), those with a good level of Jyutping expertise exhibited either a right-ear advantage or bilateral processing during lexical tone identification and contour tone discrimination, respectively. As for the effect of linguistic-processing demand, while an LEA was found in acoustic/phonetic perception situations, this advantage disappeared and was replaced by a bilateral pattern in conditions that involved a greater extent of linguistic processing, suggesting an increased involvement of the left hemisphere. Regarding the effect of tone type, both groups showed an LEA in level tone discrimination, but only the Jyutping group demonstrated a bilateral pattern in contour tone discrimination. Overall, knowledge of written codes of tones, greater degree of linguistic processing and contour tone processing seem to influence the brain lateralization of lexical tone processing in native listeners of Cantonese by increasing the recruitment of the left-hemisphere language network.

Lexical tone perception and production in Cantonese-speaking children with childhood apraxia of speech: a pilot study

ABSTRACT Childhood apraxia of speech (CAS) is a paediatric motor speech disorder. We investigated the lexical tone perception and production abilities of children with CAS and the relationships between the two. Three children with CAS, aged between 3;7 and 5;8, were given the Cantonese Tone Identification Test (CANTIT) and the Hong Kong Cantonese Articulation Test (HKCAT) for assessment of tone perception and production, respectively. Accuracy and error patterns were investigated based on their performance on the two tests. Correlation analysis was performed on children’s perception and production scores. Two children scored at the lowest rank on the CANTIT, while one child obtained a Z score of 0. All children scored three standard deviations below the mean on the HKCAT. No statistical differences were found among the six tones with respect to perception accuracy, H(5) = 3.731, p = 0.589. Error analysis showed that children with CAS demonstrated more confusion on perceiving tones compared with TD peers. There were no main effects for task (F(1,2) = 0.040, p = 0.859) or tone (F(5,10 = 0.997, p = 0.467); nor were there task or tone interaction effects on perception versus production accuracy (F(5,10) = 1.772, p = 0.206). Tone perception and production accuracy were not significantly correlated (r2 = 0.181, p = 0.078). Tone perception deficits were evident in two out of three children with CAS, while all children had lexical tone production difficulties. In this small sample, tone production was more universally affected than tone perception.

Seeing lexical tone: Head and face motion in production and perception of Cantonese lexical tones

Previous studies show that lexical tones can be discriminated visually, but the locus of this information is unknown. Here we investigate the role of visual face and head information in the production and perception of the six Cantonese lexical tones. Experiment 1 (speech production) showed that tone category membership is predicted independently by each of three visual components, Head-only, Face-only, and combined Face&Head motion, that Face&Head combined is a better predictor than the sum of Head-only and Face-only, that Head-only was a better predictor than Face-only, and that up-down head motion may be involved. In Experiment 2 (speech perception) discrimination of Cantonese tones and phones (consonants and vowels) was investigated in Auditory-Only (AO), Visual-Only (VO), and Auditory-Visual (AV) presentations of Face-only, Head-only or combined Face&Head information. There was successful visual discrimination of both phones and tones, but in different manners. For VO, face movement (Face-only, Face&Head) was sufficient for Phone discrimination, whereas both head and face (Face&Head) were necessary for Tone discrimination; and Phone discrimination was better for Face-only than Head-only, whereas Tone discrimination was the better for Head-only than Face-only. For visual augmentation of auditory information, (AV-AO)/AO), for Phones there was significant facilitation in Head-only and Face-only, but not Face&Head, whereas for Tones there was significant facilitation only in the Face&Head condition. Overall, head motion is integrally involved in the differential production of Cantonese tones and, as for consonants and vowels, there is visual perception of lexical tone, albeit based on entirely different cues: face motion is sufficient for phone perception (head motion is not necessary), whereas head motion is necessary but not sufficient for tone perception (Face&Head required). Head motion is integral both to the differential production of Cantonese tones and to the visual discrimination of those tones.