A Review of Speech Perception of Mandarin-Speaking Children With Cochlear Implantation

Objective: This paper reviewed the literature on the development of and factors affecting speech perception of Mandarin-speaking children with cochlear implantation (CI). We also summarized speech outcome measures in standard Mandarin for evaluating auditory and speech perception of children with CI.Method: A comprehensive search of Google Scholar and PubMed was conducted from March to June 2021. Search terms used were speech perception/lexical tone recognition/auditory perception AND cochlear implant AND Mandarin/Chinese.Conclusion: Unilateral CI recipients demonstrated continuous improvements in auditory and speech perception for several years post-activation. Younger age at implantation and longer duration of CI use contribute to better speech perception. Having undergone a hearing aid trial before implantation and having caregivers whose educational level is higher may lead to better performance. While the findings that support the use of CI to improve speech perception continue to grow, much research is needed to validate the use of unilateral and bilateral implantation. Evidence to date, however, revealed bimodal benefits over CI-only conditions in lexical tone recognition and sentence perception in noise. Due to scarcity of research, conclusions on the benefits of bilateral CIs compared to unilateral CI or bimodal CI use cannot be drawn. Therefore, future research on bimodal and bilateral CIs is needed to guide evidence-based clinical practice.

Expanding the gestural model of lexical tone: evidence from two dialects of Serbian

Featural and gestural models of tone differ on the degree to which they include timing information in the representation. However, both assume some kind of simultaneity between tones and their tone-bearing units, where featural models emphasize the role of acoustic relationships and gestural models instead emphasize articulatory coordination. We present the results of two acoustic production studies on two dialects of Serbian, a lexical pitch accent language. In the Belgrade dialect, pitch accents are aligned relatively late in the tone-bearing unit, while in the Valjevo dialect, pitch accents are phonetically retracted, sometimes into the preceding syllable. We varied the syllable onsets of tone-bearing units in falling (experiment 1) and rising (experiment 2) pitch accents, and measured the effects on F0 contours. Despite these differences in phonetic alignment, the phonological system is the same in both dialects. We argue that this apparent mismatch between the phonology and phonetics can be expressed straightforwardly in the Articulatory Phonology framework by allowing tone gestures to coordinate with other gestures in all the ways that segmental gestures can, rather than restricting tone to c-center coordination.

Relative Weights of Temporal Envelope Cues in Different Frequency Regions for Mandarin Vowel, Consonant, and Lexical Tone Recognition

Objectives: Mandarin-speaking users of cochlear implants (CI) perform poorer than their English counterpart. This may be because present CI speech coding schemes are largely based on English. This study aims to evaluate the relative contributions of temporal envelope (E) cues to Mandarin phoneme (including vowel, and consonant) and lexical tone recognition to provide information for speech coding schemes specific to Mandarin.Design: Eleven normal hearing subjects were studied using acoustic temporal E cues that were extracted from 30 continuous frequency bands between 80 and 7,562 Hz using the Hilbert transform and divided into five frequency regions. Percent-correct recognition scores were obtained with acoustic E cues presented in three, four, and five frequency regions and their relative weights calculated using the least-square approach.Results: For stimuli with three, four, and five frequency regions, percent-correct scores for vowel recognition using E cues were 50.43–84.82%, 76.27–95.24%, and 96.58%, respectively; for consonant recognition 35.49–63.77%, 67.75–78.87%, and 87.87%; for lexical tone recognition 60.80–97.15%, 73.16–96.87%, and 96.73%. For frequency region 1 to frequency region 5, the mean weights in vowel recognition were 0.17, 0.31, 0.22, 0.18, and 0.12, respectively; in consonant recognition 0.10, 0.16, 0.18, 0.23, and 0.33; in lexical tone recognition 0.38, 0.18, 0.14, 0.16, and 0.14.Conclusion: Regions that contributed most for vowel recognition was Region 2 (502–1,022 Hz) that contains first formant (F1) information; Region 5 (3,856–7,562 Hz) contributed most to consonant recognition; Region 1 (80–502 Hz) that contains fundamental frequency (F0) information contributed most to lexical tone recognition.

Auditory-Motor Mapping Training Facilitates Speech and Word Learning in Tone Language–Speaking Children With Autism: An Early Efficacy Study

Purpose It has been reported that tone language–speaking children with autism demonstrate speech-specific lexical tone processing difficulty, although they have intact or even better-than-normal processing of nonspeech/melodic pitch analogues. In this early efficacy study, we evaluated the therapeutic potential of Auditory-Motor Mapping Training (AMMT) in facilitating speech and word output for Mandarin-speaking nonverbal and low-verbal children with autism, in comparison with a matched non–AMMT-based control treatment. Method Fifteen Mandarin-speaking nonverbal and low-verbal children with autism spectrum disorder participated and completed all the AMMT-based treatment sessions by intoning (singing) and tapping the target words delivered via an app, whereas another 15 participants received control treatment. Generalized linear mixed-effects models were created to evaluate speech production accuracy and word production intelligibility across different groups and conditions. Results Results showed that the AMMT-based treatment provided a more effective training approach in accelerating the rate of speech (especially lexical tone) and word learning in the trained items. More importantly, the enhanced training efficacy on lexical tone acquisition remained at 2 weeks after therapy and generalized to untrained tones that were not practiced. Furthermore, the low-verbal participants showed higher improvement compared to the nonverbal participants. Conclusions These data provide the first empirical evidence for adopting the AMMT-based training to facilitate speech and word learning in Mandarin-speaking nonverbal and low-verbal children with autism. This early efficacy study holds promise for improving lexical tone production in Mandarin-speaking children with autism but should be further replicated in larger scale randomized studies. Supplemental Material https://doi.org/10.23641/asha.16834627

Music Does Not Facilitate Lexical Tone Normalization: A Speech-Specific Perceptual Process

Listeners utilize the immediate contexts to efficiently normalize variable vocal streams into standard phonology units. However, researchers debated whether non-speech contexts can also serve as valid clues for speech normalization. Supporters of the two sides proposed a general-auditory hypothesis and a speech-specific hypothesis to explain the underlying mechanisms. A possible confounding factor of this inconsistency is the listeners’ perceptual familiarity of the contexts, as the non-speech contexts were perceptually unfamiliar to listeners. In this study, we examined this confounding factor by recruiting a group of native Cantonese speakers with sufficient musical training experience and a control group with minimal musical training. Participants performed lexical tone judgment tasks in three contextual conditions, i.e., speech, non-speech, and music context conditions. Both groups were familiar with the speech context and not familiar with the non-speech context. The musician group was more familiar with the music context than the non-musician group. The results evidenced the lexical tone normalization process in speech context but not non-speech nor music contexts. More importantly, musicians did not outperform non-musicians on any contextual conditions even if the musicians were experienced at pitch perception, indicating that there is no noticeable transfer in pitch perception from the music domain to the linguistic domain for tonal language speakers. The findings showed that even high familiarity with a non-linguistic context cannot elicit an effective lexical tone normalization process, supporting the speech-specific basis of the perceptual normalization process.

Lexical tone contrast in Izon as ubiquitous floating tone

This paper establishes the lexical tone contrasts in the Nigerian language Izon, focusing on evidence for floating tone. Many tonal languages show effects of floating tone, though typically in a restricted way, such as occurring with only a minority of morphemes, or restricted to certain grammatical environments. For Izon, the claim here is that all lexical items sponsor floating tone, making it ubiquitous across the lexicon and as common as pre-associated tone. The motivation for floating tone comes from the tonal patterns of morphemes in isolation and within tone groups. Based on these patterns, all lexical morphemes are placed into one of four tone classes defined according to which floating tones they end in. This paper provides extensive empirical support for this analysis and discusses several issues which emerge under ubiquitous floating tone. Issues include the principled allowance of OCP(T) violations, and the propensity for word-initial vowels and low tone to coincide.

Separating the Novel Speech Sound Perception of Lexical Tone Chimeras From Their Auditory Signal Manipulations: Behavioral and Electroencephalographic Evidence

Previous research has shown the novelty of lexical-tone chimeras (artificially constructed speech sounds created by combining normal speech sounds of a given language) to native speakers of the language from which the chimera components were drawn. However, the source of such novelty remains unclear. Our goal in this study was to separate the effects of chimeric tonal novelty in Mandarin speech from the effects of auditory signal manipulations. We recruited 20 native speakers of Mandarin and constructed two sets of lexical-tone chimeras by interchanging the envelopes and fine structures of both a falling/yi4/and a rising/yi2/Mandarin tone through 1, 2, 3, 4, 6, 8, 16, 32, and 64 auditory filter banks. We conducted pitch-perception ability tasks via a two-alternative, forced-choice paradigm to produce behavioral (versus physiological) pitch perception data. We also obtained electroencephalographic measurements through the scalp-recorded frequency-following response (FFR). Analyses of variances and post hoc Greenhouse-Geisser procedures revealed that the differences observed in the participants’ reaction times and FFR measurements were attributable primarily to chimeric novelty rather than signal manipulation effects. These findings can be useful in assessing neuroplasticity and developing speech-processing strategies.

The Effects of Lexical Tone Awareness on Early Word Recognition, Word Reading, and Spelling From Dictation of Thai Children: A Longitudinal Study

In tonal languages such as Thai, lexical tone (the pitch of a syllable) affects word meaning. This study examined the effects of lexical tone awareness (LTA) on early word recognition and the relationship between these abilities and word reading and spelling in subsequent grades. A longitudinal design was used to assess reading-related skills in 259 Thai children, first in kindergarten (130 girls, Mage=67.25months) and later in Grade 3 (Mage=102.25months). In kindergarten, the children were tested on lexical tone identification and differentiation, early literacy skills, non-verbal IQ, and early word recognition. In Grade 3, they were tested on word reading and spelling from dictation. The hierarchical regression analyses showed that the lexical tone identification skills in kindergarten accounted for 2% of the unique variance in early word recognition. However, none of the LTA skills could predict word reading and spelling from dictation after controlling for other literacy-related skills. These findings suggest that LTA skill positively associated with early word recognition at the kindergarten level, but not for word reading and spelling from dictation at a Grade 3 level.