The duration aspect of tones - Semantic Scholar

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dipping (or just low) and falling respectively. It is repeatedly observed that Tone2 is longer than Tone4. This is consi
The duration aspect of tones Jiahong Yuan University of Pennsylvania Tone is realized on and synchronized with its tone-bearing unit. On the one hand, the duration of the tone-bearing unit is affected by many contextual factors such as speaking rate and intonation. On the other hand, tone as an articulatory event has an intrinsic duration. For example, it takes longer time to realize a rising tone than a falling one over the same pitch range, because the maximum speed of pitch change is slower for pitch rises (Ohala and Ewan 1973). The question then is, how do the two aspects interact, is one more basic than the other? The answer is not easy to find. For example, it is observed that long vowels and sonorant rimes are more likely to carry contour tones (Gordon, 2001). The phonological accounts for the distribution of contour tones have made different assumptions (explicitly or implicitly) about which is more basic in determining the duration of a tone, the tone itself or its tone-bearing unit: A contour tone occupies two moras or tonal positions (Duanmu 1994, Akinlabi and Liberman 2001). ⇒ Tone-bearing units are more basic. When a contour tone is associated with a short tone-bearing unit, the rankings of the faithfulness constraints on tone and duration determine whether contour flattening or rime lengthening will occur (Zhang 2000). ⇒ Neither tone nor its tone-bearing unit plays a deterministic role, the two interact with each other in a Optimality-Theoretic grammar. The durational properties of contour tones are better explained in terms of the interplay of articulatory and perceptual effects in tone realization (Yu 2010). ⇒ Tones are more basic. I will present several tone duration patterns in Mandarin Chinese, which shed light on the question. 1. Tone2 is longer than Tone4 There  are  four  lexical  tones  in  Mandarin  Chinese,  referred  to  as  Tone1,  Tone2,   Tone3  and  Tone4.  The  F0  contours  of  the  tones  in  isolation  are  high  level,  rising,  low   dipping  (or  just  low)  and  falling  respectively.            It  is  repeatedly  observed  that  Tone2  is  longer  than  Tone4.  This  is  consistent  with   that  pitch  rises  take  longer  time  than  pitch  falls.  But  on  the  other  hand,  Tone2  has  a   smaller  pitch  range  than  Tone4.  Therefore,  the  underlying  rising  and  falling  targets   might  not  be  adequate  to  explain  the  duration  difference  between  the  two  tones   (Phonetic  evidence  in  support  of  unitary  contours  in  Chinese  tonal  representation   can  be  found  in  Xu  1999).  By  examining  the  F0  trajectories  of  the  rising  and  falling   tones  when  they  are  focused,  we  can  see  that  Tone2  has  a  lengthened  L  and  a  raised  

H  whereas  Tone4  has  only  a  raised  H  but  not  a  lengthened  L.  This  suggests  that  the   underlying  representation  of  Tone2  is  L*+R  and  that  of  Tone4  is  H*+F.  The  duration   difference  between  Tone2  and  Tone4  thus  results  from  two  combined  effects:  low   tones  are  longer  than  high  tones,  and  rising  tones  are  longer  than  falling  tones.  

Figure 1. The beginning Tone2 is focused (dark circles) vs. unfocused (open circles)

Figure 2. The beginning Tone4 is focused (dark circles) vs. unfocused (open circles).

2. The effect of speaking rate on the duration of sentence final Tone2 and Tone4. Thirty speakers of Mandarin Chinese read a list of sentences, which are minimal pairs of statements and questions, in slow, normal, and fast speaking rates. The effect of speaking rate on the duration of sentence final Tone2 and Tone4 in statements is shown in Figure 3. We can see that speaking rate has similar effects on Tone2 and Tone4, and also that the duration difference between Tone2 and Tone4 is consistent across all speaking rates. This result suggests that the effects of speaking rate and tonal targets on the duration of tone are orthogonal.

Figure 3. The effect of speaking rate on the duration of sentence final Tone2 and Tone4.

3. The effect of intonation on the duration of sentence final Tone2 and Tone4. The effect of intonation on the duration of sentence final Tone2 and Tone4 is shown in Figure 4. We can see that the  final  Tone4  is  longer  in  question  intonation  than  in  

statement  intonation  whereas  the  final  Tone2  has  similar  duration  in  the  two   intonation  types,  and  the  pattern  is  the  same  across  all  speaking  rates.            First,  this  result  confirms  that  the  speaking  rate  effect  is  orthogonal  to  the  effect  of   tonal  targets  on  the  duration  of  tone.  Secondly,  question  intonation  has  different   effects  on  the  duration  of  final  Tone2  and  Tone4.  Yuan  (2004)  proposed  that  a   mechanism  of  question  intonation  in  Mandarin  Chinese  is  to  change  the  slope  of   contour  tones,  i.e.,  to  flatten  the  final  falling  tone  and  to  steepen  the  final  rising  tone.   The  change  of  tonal  targets  is,  however,  blind  to  its  consequence  to  the  duration  of   tone.    

Figure 4. The effect of intonation on the duration of sentence final Tone2 and Tone4.

In summary, the study suggests that tonal targets and tone-bearing units have orthogonal effects on tonal duration. The effect of tonal targets on its duration is not controlled, it is blind to the output duration. To investigate the duration aspect of tones may inform a full understanding of the underlying representation of tone. References: Akinlabi, A. and Liberman, M. (2001). “Tonal Complexes and Tonal Alignment,” NELS 31. Duanmu, S. (1994). “Against contour tone units,” Linguistic Inquiry, 25, 555-608. Gordon, M. (2001). “A typology of contour tone restriction,” Studies in Language, 25, 405-444. Ohala, J. J., and Ewan, W. G. (1973). “Speed of pitch change,” J. Acoust. Soc. Am., 53, 345. Xu, Y. (1999). “Effects of tone and focus on the formation and alignment of F0 contours,” Journal of Phonetics 27: 55-105. Yu, A. (2010). “Tonal effects on perceived vowel duration,” Laboratory Phonology 10. Yuan, J. (2004). Intonation in Mandarin Chinese: Acoustics, Perception, and Computational Modeling, PhD dissertation, Cornell University. Zhang, J. (2000). A Formal Optimality-Theoretic Model for Tone-Duration Interaction, PhD dissertation, UCLA.