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CHAPTER 2 LITERATURE REVIEW

2.6 Mandarin tone

2.6.1 The perception of Mandarin Chinese tones

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2.4.4 The acoustic-phonetic cues of affricates

There are three pairs of affricates in Mandarin, /t /, /tȹ /, /t /, /tȹ /, /ts/, and /tȹs/.

According to Ladefoged (2000), an affricate is simply a sequence of a stop followed

by a homorganic fricative. Therefore, it can be inferred that affricates have the

acoustic-phonetic characteristics of both stops and fricatives.

2.5 The acoustic-phonetic cues of the vowels in Taiwan Mandarin

Phonetically speaking, there are overall 12 vowels in Taiwan Mandarin,

including 4 high vowels ([i], [u], [y], and [ ]), 2 low vowels ([a] and [ ]), as well as 6

mid vowels ([e], [ ], [ə], [ ], [o], and [ ]). Vowels have very different phonetic cues

from consonants. First of all, vowels have much longer duration than consonants.

Second, the formants of vowels are much clearer than those of consonants. Third, the

energy of vowels is stronger than that of consonants, causing darker spectrogram.

Fourth, the F0 in vowels displays the tones in Mandarin. From the acoustic-phonetic

cues, vowels can be distinguished from consonants.

2.6 Mandarin tone

2.6.1The perception of Mandarin Chinese tones

Lexical tones are pitch patterns that can distinguish lexical meanings in a given

language. In Mandarin Chinese, tones, like the aspirated and unaspirated stops, are

phonemic features that can differentiate word meanings. Mandarin Chinese

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phonemically distinguishes four tones, which are Tone 1, with high-level pitch, Tone

2, with high-rising pitch, Tone 3, with low falling-rising pitch, and Tone 4, with

high-falling pitch (Chao, 1948). The same syllable structure can have different

meanings if it carries different tones. For instance, ma with Tone 1 has the meaning of

‘mother’; ma with Tone 2 has the meaning of ‘numbness’; ma with Tone 3 has the

meaning of ‘horse’; ma with Tone 4 has the meaning of ‘scold’.

There are several factors that can affect the perception of Mandarin Chinese

tones. First, fundamental frequency plays a role in the Mandarin Chinese tone

perception. Previous acoustic studies have found that the F0 height and F0 contour are

the acoustic cues for Mandarin Chinese tone perception. Howie (1976) performed the

tone perception experiments to test whether the participants could identify the correct

tones of the stimuli. Howie designed three contrasted conditions, which were

synthetic speech with natural F0 patterns, synthetic speech with the monotonic F0

contour, and synthetic speech sounding like a whisper. The results showed that

subjects easily recognized the synthetic speech which F0 patterns were maintained.

Gandour (1984) and Tseng & Cohen (1985) indicated that both F0 height and F0

contour are very crucial acoustic cues for Mandarin tone perception. Neither one can

be missed. Moore and Jongman (1997) differentiated Tone 2 from Tone 3 in terms of

two characteristics. One is turning point, which is the point in time at which the tone

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changes from falling to rising, and the other is ∆F0, which is the F0 change from the

onset to the turning point. Moore and Jongman found that the turning point of Tone 2

is earlier than that of Tone 3, and the ∆F0 of Tone 2 is smaller than that of Tone 3.

Comparing the acoustic cues of Tone 3 and Tone 4, Garding et al. (1986) found that

the stimuli which have the early peak of pitch and fall dramatically after the turning

point tend to be perceived as Tone 4. The stimuli which stay at low F0 range and have

long duration tend to be recognized as Tone 3. This study demonstrates that F0

contour is of paramount importance for Mandarin tone perception.

The second factor that can influence the perception of Mandarin Chinese tones is

the temporal properties of tones. According to the production data, Nordenhake and

Svantesson (1983) found that the duration of Tone 3 is the longest, which is only

slightly longer than that of Tone 2, while the duration of Tone 4 is the shortest. Given

that the F0 contours are similar between Tone 2 and Tone 3, Nordenhake and

Svantesson (1983) further indicated that Tone 2 could be perceived as Tone 3 if it is

lengthened.

In addition to F0 and duration, amplitude can also affect the perception of

Mandarin Chinese tones though only to a small extent. Whalen and Xu (1992)

designed stimuli whose formant structures and F0 contours were removed, but the

amplitude cues of the stimuli were reserved, and then they asked the participants to

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identify the stimuli. The results demonstrated that participants could successfully

identify Tone 2, Tone 3, as well as Tone 4, but fail to recognize Tone 1.

From the above mentioned studies on acoustic phonetic characteristics of

Mandarin Chinese tones, it is clear that fundamental frequency, turning point, ∆F0,

duration, and amplitude are the acoustic cues which play a critical role in the

perception of Mandarin Chinese tones. Nevertheless, the acoustic quality of tones can

be influenced by the surrounding context, which may also affect the perception of

tones.

Shen (1990) studied the tonal coarticulation of Mandarin Chinese and found that

tonal coarticulation not only affects the F0 height of the onset or offset, but it affects

the F0 height of the entire word. The tones that are most easily to be affected are those

which follow Tone 1 and Tone 2. Both Tone 1 and Tone 2 have high offset F0 value,

which can raise the entire F0 value of the following tones. In addition, the high onset

F0 value of Tone 4 also has the effect of raising the whole F0 value of the preceding

tones. Unlike Tone 1, the offset of Tone 2, and onset of Tone 4, the onset of Tone 2 as

well as Tone 3, whose onset F0 value sits on the middle of the frequency range, do not

have the ability of raising the entire F0 value of the preceding tones. In addition to all

these findings above, shen also found that the tonal contour does not change even if

the tone’s entire F0 value has risen. Shen finally pointed out that tonal coarticulation

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cannot extend beyond one syllable.