Contributions of the Fundamental, Resolved Harmonics, and Unresolved Harmonics in Tone-Phoneme Identification

Abstract

Researchers describe Mandarin Chinese tone phonemes by their fundamental frequency (Fo) contours. However, tone phonemes are also comprised of higher harmonics that also may cue tone phonemes. We measured identification thresholds of acoustically filtered tone phonemes and found that higher harmonics, including resolved harmonics above the Fo and unresolved harmonics, cued tone phonemes. Resolved harmonics cued tone phonemes at lower intensity levels suggesting they are more practical tone-phoneme cues in everyday speech. The clear implication is that researchers should use the Fo only as a benchmark when describing tone-phoneme contours, recognizing that higher harmonics also cue tone phonemes. These results also help explain why tone-language speakers can identify tone phonemes over a telephone that attenuates selective frequencies, and suggests that hearing-impaired tone-language speakers may still identify tone phonemes when their hearing loss attenuates selective frequencies.

Detection of spatial cues in linear and logarithmic frequency-modulated sweeps

“…Most formant transitions have durations of less than 50 msec, and very brief FM sweeps of 5-20 msec with rates exceeding 30 octaves per second have been used in several studies to examine processing of formant transitions (A. M. Liberman et al, 1956;Luo et al, 2007;Miller & Liberman, 1979). Rapid FM sweeps have also been employed in the study of tonal languages (e.g., Chinese or Thai), where pitch contour variations affect lexical distinction (Howie, 1976;Luo et al, 2007;Stagray, Downs, & Sommers, 1992). The study of FM transitions in speech has also had practical applicability for language processing by children afflicted with language-based learning impairment (LLI).…”

The perception of FM sweeps by Chinese and English listeners

“…Poeppel, 2003). Importantly, supra-segmental FM forms the basis for the lexical distinctions in tone languages, such as Mandarin Chinese or Thai, both of which use highly constrained and parameterized pitch contour variations to make lexical distinctions (Howie, 1976;Stagray et al, 1992). For example, the segmental sequence, [ma], has four distinct meanings in Mandarin Chinese when spoken with different supra-segmental (or 'global') pitch contours.…”

Hearing Aid Low Frequency Cut: Effect on Mandarin Tone and Vowel Perception in Normal-Hearing Listeners

“…On average, greater than 80% tone recognition levels were achieved for almost all low frequency cuts and S/N ratios, except for condition LC18 and S/N -10. A 66.8% recognition level was reached in LC18 and S/N -10, indicating that harmonic cues might play as important a role in such adverse listening conditions for tone perception, as they do in quiet [6] . In brief, a tone recognition score above 80% was maintained regardless of the influence of low frequency cuts and noise for normal-hearing listeners, except for the very adverse listening condition LC18 and S/N -10.…”

“…Stagray et al [6] further explored the role of harmonics by measuring the identification thresholds of acoustically filtered Mandarin phonemes and found that higher harmonics still cued tone phonemes. These findings were consistent with predictions based on our knowledge of pitch perception for nonspeech, complex tones.…”