Chao-Yang Lee

Does horse activate mother? Processing lexical tone in form priming

Lexical tone languages make up the majority of all known languages of the world, but the role of tone in lexical processing remains unclear. In the present study, four form priming experiments examined the role of Mandarin tones in constraining lexical activation and the time course of the activation. When a prime and a target were related directly in form (e.g., lou3 `hug — lou2 `hall), competitors that differed from the prime in tone failed to be activated, indicating the use of tonal information to distinguish between segmentally identical words. When a prime and a target were not form-related but were related through a third word that was not actually presented (e.g., lou3 `hug — jian4zhu0 `building, where lou3 is form-related to lou2 `hall, which was semantically related to jian4zhu0), a mismatch in tone prevented activation of minimal tone pairs at 250ms interstimulus interval (ISI) but did not prevent activation at 50ms ISI. These results indicate that tonal information is used on-line to reduce the number of activated candidates, but does not prevent the minimal tone pairs from being activated in the early phase of lexical activation.

Identification of acoustically modified Mandarin tones by native listeners

This study investigated identification of fragmented Mandarin tones by non-native listeners. Monosyllabic Mandarin words were digitally processed to generate intact, silent-center, center-only, and onset-only syllables. The syllables were recorded with two carrier phrases such that the offset of the carrier tone and the onset of the target tone were either continuous or discontinuous in fundamental frequency (F0). The syllables were presented with an original carrier phrase, excised from the carrier phrase, or excised and cross-spliced with another carrier phrase. Response accuracy and reaction time were measured, and tone confusion patterns were analyzed. Overall, tone identification varied as a function of modification and tone. Intact and center-only syllables were identified more accurately than silent-center and onset-only syllables. Tone 2 was consistently the most challenging tone to identify. Although the performance level of the third-year students approached that of native listeners reported in Lee, Tao, and Bond (2008), the non-native listeners did not show evidence of using coarticulatory information. Nonetheless, the continuity or discontinuity in F0 between the carrier and target tones did affect tone identification, suggesting the influence of context in non-native tone identification.

Perception of musical pitch and lexical tones by Mandarin-speaking musicians

The relationship between music and language processing was explored in two perception experiments on the identification of musical notes and Mandarin tones. In the music task, Mandarin-speaking musicians were asked to identify musical notes of three timbres without a reference pitch. 72% of the musicians met the criterion for absolute pitch when an exact match was required, and 82% met the criterion when one-semitone errors were allowed. Accuracy of identification was negatively correlated with age of onset of musical training, and piano notes were identified more accurately than viola and pure tone stimuli. In the Mandarin task, the musicians were able to identify, beyond chance, brief Mandarin tone stimuli that were devoid of dynamic F0 information and cues commonly considered necessary for speaker normalization. Although F0 height detection was involved in both musical note and Mandarin tone identification, performances in the two tasks were not correlated. The putative link between absolute pitch and tone language experience was discussed.

Identifying isolated, multispeaker Mandarin tones from brief acoustic input: A perceptual and acoustic study

Lexical tone identification relies primarily on the processing of F0. Since F0 range differs across individuals, the interpretation of F0 usually requires reference to specific speakers. This study examined whether multispeaker Mandarin tone stimuli could be identified without cues commonly considered necessary for speaker normalization. The sa syllables, produced by 16 speakers of each gender, were digitally processed such that only the fricative and the first six glottal periods remained in the stimuli, neutralizing the dynamic F0 contrasts among the tones. Each stimulus was presented once, in isolation, to 40 native listeners who had no prior exposure to the speakers voices. Chi-square analyses showed that tone identification accuracy exceeded chance as did tone classification based on F0 height. Acoustic analyses showed contrasts between the high- and low-onset tones in F0, duration, and two voice quality measures (F1 bandwidth and spectral tilt). Correlation analyses showed that F0 covaried with the voice quality measures and that tone classification based on F0 height also correlated with these acoustic measures. Since the same acoustic measures consistently distinguished the female from the male stimuli, gender detection may be implicated in F0 height estimation when no context, dynamic F0, or familiarity with speaker voices is available.

Identification of Acoustically Modified Mandarin Tones by Non-native Listeners

This study investigated identification of fragmented Mandarin tones by non-native listeners. Monosyllabic Mandarin words were digitally processed to generate intact, silent-center, center-only, and onset-only syllables. The syllables were recorded with two carrier phrases such that the offset of the carrier tone and the onset of the target tone were either continuous or discontinuous in fundamental frequency (F0). The syllables were presented with an original carrier phrase, excised from the carrier phrase, or excised and cross-spliced with another carrier phrase. Response accuracy and reaction time were measured, and tone confusion patterns were analyzed. Overall, tone identification varied as a function of modification and tone. Intact and center-only syllables were identified more accurately than silent-center and onset-only syllables. Tone 2 was consistently the most challenging tone to identify. Although the performance level of the third-year students approached that of native listeners reported in Lee, Tao, and Bond (2008), the non-native listeners did not show evidence of using coarticulatory information. Nonetheless, the continuity or discontinuity in F0 between the carrier and target tones did affect tone identification, suggesting the influence of context in non-native tone identification.

Speaker variability and context in the identification of fragmented Mandarin tones by native and non-native listeners

Abstract This study investigated the individual and joint contribution of speaker variability, context, and type of acoustic input to the identification of Mandarin tones. Mandarin syllables produced by single vs. multiple speakers were digitally processed to generate intact, silent-center, center-only, and onset-only syllables to be presented in isolation or with a precursor carrier phrase. Forty native listeners and 55 non-native listeners were put under time pressure to identify the tones of the syllables. The results showed higher identification accuracy for single-speaker tones and tones presented in context. Tone identification accuracy also decreased as acoustic input was reduced. The speaker variability effect showed comparable magnitude for the native and non-native listeners. In contrast, non-native tone identification, compared to the native performance, was facilitated less by context and compromised more when acoustic input was minimal. Tone confusion analyses showed a Tone 2–Tone 3 confusion and a bias towards Tone 4 responses for both groups of listeners, but the patterns of confusion and bias are more variable in the non-native responses. The non-native listeners also showed inconsistent evidence of using F0 height for tone identification when acoustic input was minimal.

Identification of multi-speaker Mandarin tones in noise by native and non-native listeners

The similarities and contrasts between native and non-native identification of multi-speaker Mandarin tones in quiet and in noise were explored in a perception experiment. Mandarin tone materials produced by three male and three female speakers were presented with five levels of signal-to-noise ratios (quiet, 0, -5, -10, and -15dB) in two presentation formats (blocked by speaker and mixed across speakers) to listeners with various Mandarin experience (native, first-year, second-year, third-year, and fourth-year students). Stimuli blocked by speaker yielded higher accuracy and shorter reaction time. The additional demand of processing mixed-speaker stimuli, however, did not compromise non-native performance more than native performance. Noise expectedly compromised identification performance, although it did not compromise non-native identification more than native identification. Native listeners expectedly outperformed non-native listeners, although identification performance did not vary systematically as a function of duration of Mandarin experience. It is speculated that sources of variability in speech would affect non-native more than native tone identification only if syllable-internal, canonical F0 information is removed or altered.

Perception of musical and lexical tones by Taiwanese-speaking musicians

This study explored the relationship between music and speech by examining absolute pitch and lexical tone perception. Taiwanese-speaking musicians were asked to identify musical tones without a reference pitch and multispeaker Taiwanese level tones without acoustic cues typically present for speaker normalization. The results showed that a high percentage of the participants (65% with an exact match required and 81% with one-semitone errors allowed) possessed absolute pitch, as measured by the musical tone identification task. A negative correlation was found between occurrence of absolute pitch and age of onset of musical training, suggesting that the acquisition of absolute pitch resembles the acquisition of speech. The participants were able to identify multispeaker Taiwanese level tones with above-chance accuracy, even though the acoustic cues typically present for speaker normalization were not available in the stimuli. No correlations were found between the performance in musical tone identification and the performance in Taiwanese tone identification. Potential reasons for the lack of association between the two tasks are discussed.

Effects of speaker variability and noise on Mandarin tone identification by native and non-native listeners

Abstract The purpose of this study was to examine whether speaker variability and noise affect native and non-native listeners differently in Mandarin tone perception. Multi-speaker tone stimuli embedded in speech-shaped noise were presented blocked by speaker or mixed across speakers. The listeners included 20 native listeners and 33 non-native listeners with various degree of Mandarin proficiency, defined by years of Mandarin instruction and baseline performance. The results showed that the mixed-speaker presentation did not affect non-native listeners disproportionately, suggesting that speaker variability did not pose a special challenge to non-native listeners. In contrast, noise disrupted native and non-native perception differently, but it was the listeners with higher Mandarin proficiency that were affected disproportionately. These findings suggest that that not all sources of acoustic variability are equally disruptive to native and non-native speech perception.

Effects of speaker variability and noise on Mandarin fricative identification by native and non-native listeners

Speaker variability and noise are two common sources of acoustic variability. The goal of this study was to examine whether these two sources of acoustic variability affected native and non-native perception of Mandarin fricatives to different degrees. Multispeaker Mandarin fricative stimuli were presented to 40 native and 52 non-native listeners in two presentation formats (blocked by speaker and mixed across speakers). The stimuli were also mixed with speech-shaped noise to create five levels of signal-to- noise ratios. The results showed that noise affected non-native identification disproportionately. By contrast, the effect of speaker variability was comparable between the native and non-native listeners. Confusion patterns were interpreted with reference to the results of acoustic analysis, suggesting native and non-native listeners used distinct acoustic cues for fricative identification. It was concluded that not all sources of acoustic variability are treated equally by native and non-native listeners. Whereas noise compromised non-native fricative perception disproportionately, speaker variability did not pose a special challenge to the non-native listeners.