Page 28 - Volume 12, Issue 2 - Spring 2012

Recording brain waves from a group of Mandarin-speaking subjects, Luo and colleagues (2006) found a parsimonious answer in that hemisphere specialization of tonal processing is timing dependent. In early pre-attentive processing (<160 ms), like music, tonal information is processed by the right hemisphere, in which pitch information is presumably extracted. After that time mark and the extraction of pitch, tonal information encoding the lexical meaning is then processed, and guess where—in the left hemisphere. Combining the results from the Wong and Luo studies, we can infer that the failure for some English-speakers to learn Mandarin tones is not due to their inability to process pitch information in the right hemisphere, but rather their ineffi- ciency to convert this pitch information into lexical meaning in the left hemisphere.
Processing deficits in both the ear and the brain con- tribute to tonal language perception and development by hearing-impaired listeners. In post-lingually hearing- impaired listeners, the deficit is mostly in the ear due to either poor spectral resolution as a result of hearing loss (Wang et al., 2010), or lack of proper pitch extraction and delivery in auditory prostheses (Zeng et al., 2008). For exam- ple, current cochlear implants do not extract, nor can they properly deliver, the salient pitch cue conveyed by the funda- mental frequency or its lower harmonics. Instead, they only extract and deliver the less salient temporal envelope cue. As a result, tones are extremely difficult to produce and perceive by deaf children using a cochlear implant (Han et al., 2007; Lee et al., 2010). One solution to this problem is to deliver the fundamental frequency information acoustically via a hear- ing aid in the residual low-frequency region (<500 Hz) and simultaneously the high-frequency temporal envelope infor- mation via a cochlear implant. This “hybrid hearing” can improve tonal information transfer and speech perception in noise (Kong et al., 2005; Qin and Oxenham, 2006). Surprisingly, introduction of the tonal information via hear- ing aids significantly helps cochlear-implant children to learn English, particularly the expressive part of the language (Nittrouer and Chapman, 2009). After all, tones are not just for tonal languages.AT
References
Bendor, D., and Wang, X. (2005). “The neuronal representation of pitch in primate auditory cortex.” Nature 436, 1161–1165.
Dediu, D., and Ladd, D. R. (2007). “Linguistic tone is related to the population frequency of the adaptive haplogroups of two brain size genes, ASPM and Microcephalin,” Proceed. Natl. Acad. Sci. of the United States of America 104, 10944–10949.
Fu, Q. J., Zeng, F. G., Shannon, R. V., and Soli, S. D. (1998). “Importance of tonal envelope cues in Chinese speech recogni- tion,” J. Acoust. Soc. Am. 104, 505–510.
Han, D., Zhou, N., Li, Y., Chen, X., Zhao, X., and Xu, L. (2007). “Tone production of Mandarin Chinese speaking children with cochlear implants,” Intl. J. Pediatric Otorhinolaryngol. 71,
875–880.
Haviland, W. A., Prins, H. E. L., Walrath, D., and McBride, B.
(2007). Anthropology: The Human Challenge (12th ed.)
(Thomson Higher Education, Belmont, CA).
Kong, Y. Y., and Zeng, F. G. (2006). “Temporal and spectral cues in
Mandarin tone recognition” J. Acoust. Soc. Am. 120, 2830–2840. Kong, Y. Y., Stickney, G. S., and Zeng, F.-G. (2005). “Speech and melody recognition in binaurally combined acoustic and electric
hearing,” J. Acoust. Soc. Am. 117, 1351–1361.
Lee, C. Y. (2007). “Does horse activate mother? Processing lexical
tone in form priming,” Language and Speech 50, 101–123.
Lee, K. Y., van Hasselt, C. A., and Tong, M. C. (2010). “Lexical tone perception ability of profoundly hearing-impaired children: Performance of cochlear implant and hearing aid users,” Otolol.
and Neurotol. 31, 1079–1087.
Liang, Z. A. (1963). “汉语普通话中声调的听觉辨认依据 The
auditory discrimination basis of tone recognition in Standard
Chinese,” Acta Physiol. Sinica 26, 85–91.
Luo, H., Ni, J. T., Li, Z. H., Li, X. O., Zhang, D. R., Zeng, F.-G., and
Chen, L. (2006). “Opposite patterns of hemisphere dominance for early auditory processing of lexical tones and consonants.” Proc. Natl. Acad. Sci. of the United States of America 103, 19558–19563.
Luo, X., Fu, Q. J., Wu, H. P., and Hsu, C. J. (2009). “Concurrent- vowel and tone recognition by Mandarin-speaking cochlear implant users,” Hearing Res. 256, 75–84.
Meyer, J. (2008). “Typology and acoustic strategies of whistled lan- guages: Phonetic comparison and perceptual cues of whistled vowels,” J. Intl. Phonetic Assn. 38, 69–94.
Nittrouer, S., and Chapman, C. (2009). “The effects of bilateral elec- tric and bimodal electric–acoustic stimulation on language development,” Trends in Amplification 13, 190–205.
Oxenham, A. J., Bernstein, J. G., and Penagos, H. (2004). “Correct tonotopic representation is necessary for complex pitch percep- tion,” Proc. Natl. Acad. Sci. of the United States of America 101, 1421–1425.
Qin, M. K., and Oxenham, A. J. (2006). “Effects of introducing unprocessed low-frequency information on the reception of envelope-vocoder processed speech,” J. Acoust. Soc. Am. 119, 2417–2426.
Wang, S., Mannell, R., Newall, P., and Han, D. (2010). “Contribution of spectral cues to Mandarin lexical tone recogni- tion in normal-hearing and hearing-impaired Mandarin Chinese speakers,” Ear and Hearing 32, 97–103.
Whalen, D. H., and Xu, Y. (1992). “Information for Mandarin tones in the amplitude contour and in brief segments,” Phonetica 49, 25–47.
Wong, P. C., Warrier, C. M., Penhune, V. B., Roy, A. K., Sadehh, A., Parrish, T. B., and Zatorre, R. J. (2008). “Volume of left Heschl’s Gyrus and linguistic pitch learning,” Cerebral Cortex 18, 828–836.
Xu, L., and Pfingst, B. E. (2003). “Relative importance of temporal envelope and fine structure in lexical-tone perception,” J. Acoust. Soc. Am. 114, 3024–3027.
Zeng, F.-G. (2002). “Temporal pitch in electric hearing,” Hearing Res. 174, 101–106.
Zeng, F.-G., Rebscher, S., Harrison, W., Sun, X., and Feng, H. H. (2008). “Cochlear implants: System design, integration and eval- uation,” IEEE Rev. in Biomed. Eng. 1, 115–142.
Tonal Language Processing 27