© Springer-Verlag Berlin Heidelberg 2008 A New Chinese Speech Synthesis Method Apply in Chinese Poetry Learning Chengsong Zhu and Yaoting Zhu College of Information Technical Science,
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of the template is already known in the database Hence, the stroke sequence can be easily verified based on the stroke correspondence
Computational complexity We apply our pruning strategy to the graph matching,
and compare the computational time with the existing method in [6] The method
in [6] also makes use of graph matching to find out the difference between the template and sample but without applying the pruning strategy From Figure 9(a),
it can be observed that the performance of finding stroke production errors for the method with and without pruning is similar However, our proposed method is faster than the one in [6] as illustrated in Figure 9(b)
The results show that our method can handle more kinds of handwriting errors such
as stroke production errors, spatial relationship errors and stroke sequence error com-pared with existing methods While our method can locate more kinds of handwriting errors with less computational time, the accuracy of our approach also outperforms existing methods
4 Conclusion
In this paper we have used the attributed relational graph to represent a Chinese handwriting character incorporating the spatial relationship information between strokes A refined interval relationship with more granular levels is proposed to model the Chinese characters A novel interval neighborhood graph is also proposed to com-pute the distances among the refined interval relationships A pruning strategy is adopted to assist the A* algorithm in searching for the optimal matching and lowering the computational complexity The experiments show that our proposal can handle more kinds of handwriting errors than existing methods with less computational time
To further improve the performance of our method, future work may focus on
im-proving the current definition of relationship by combining the relationship along x-axis and y-x-axis to form a new relationship, and find a more computationally efficient
pruning strategy based on the new relationship
Acknowledgments
The work described in this paper was fully supported by a grant from City University
of Hong Kong (Project No 7001711)
References
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7 Tang, K.T., Leung, H.: Reconstructing the correct writing sequence from a set of Chinese character strokes In: Matsumoto, Y., Sproat, R.W., Wong, K.-F., Zhang, M (eds.) IC-CPOL 2006 LNCS (LNAI), vol 4285, pp 333–344 Springer, Heidelberg (2006)
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344 (2002)
9 Tang, K.T., Li, K.K., Leung, H.: A Web-Based Chinese Handwriting Education System with Automatic Feedback and Analysis In: Liu, W., Li, Q., Lau, R (eds.) ICWL 2006 LNCS, vol 4181, pp 176–188 Springer, Heidelberg (2006)
10 Tsai, W.H., Fu, K.S.: Error-correcting isomorphisms of attributed relational graphs for pat-tern analysis IEEE Trans SMC 9, 757–768 (1979)
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2003 LNCS, vol 2726, pp 95–106 Springer, Heidelberg (2003)
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Trang 3F Li et al (Eds.): ICWL 2008, LNCS 5145, pp 356 – 365, 2008
© Springer-Verlag Berlin Heidelberg 2008
A New Chinese Speech Synthesis Method Apply in
Chinese Poetry Learning
Chengsong Zhu and Yaoting Zhu College of Information Technical Science, Nankai University, No 94, Weijin Road, Tianjin
300071, China zhuchs@nankai.edu.cn, zhuyt@nankai.edu.cn
Abstract This paper describes a new Chinese speech synthesis method apply in
Chinese poetry teaching and learning, which focus on the prosody of syllables and words in Chinese poetry As the word is a key semantic unit for Chinese poetry, we concentrate on Chinese word prosody and propose a speech synthesis method, which consider the appearance with the essence of human voice, use the homomorphism analysis over the time domain analysis to make the synthesized speech between syllables in a Chinese word sounds more natural The prosody model of the method, however comply with the reading rules of Chinese poetry, make the user to learn Chinese poetry more convenient from the acoustic per-ception level
Keywords: Chinese poetry, Speech Synthesis, PSOLA, homomorphism
1 Introduction
China is a poetry country, she had reached her golden age in Tang dynasty and Song dynasty The Chinese poetry is a quintessence of Chinese culture In modern education the poetry teaching and learning is still play an import role
To learn Chinese poetry reciting is the first step, and then comprehension Generally
we recite things by our eyes or ears Though we often get knowledge from the visual perception level, the sounding perception level can’t be ignored Sometimes we reading out loudly when we learn the poetry, actually it affects our brain through our ears The Chinese Text To Speech (hereafter call TTS) technology can translate Chinese text stored in computer into speech voices that can played through the sound devices Thus the Chinese TTS technology can help users to learn the Chinese poetry more convenient, more efficient and to make the Chinese poetry teaching more vivid
In the following, we will give the prosody feature of Chinese poetry in section 2, and then present the synthesis speech prosody model in section3, and the new speech synthesis method in section 4, followed with the experiment and conclusion in section 5
2 The Prosody Feature of the Chinese Poetry
Take a Tang poetry “床前明月光, 疑是地上霜 举头望明月, 低头思故乡.” as ex-ample It will be segmented into “床前/明月光/, 疑是/地上霜/ 举头/望/明月/, 低头/
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思 / 故 乡 /.” and the Mandarin Chinese phonetics is spell as “chuang2qian2/ ming2yue4guang1/, yi2shi4/ di4shang4shuang1/, ju3tou2/ wang4/ ming2yue4/, di1tou2/ si1/ gu4xiang1/ ”, in which the number represents the syllable tone Here we call one Chinese character as a syllable
The Chinese poetry format is strict neatly, it is often made of four or eight sentences which including five or seven syllables The poetry gives abundant information in such limited words, so a character or a word can be explained into several associate mean-ings Then the poetry often takes one syllable or one word as its reading unit
The poetry reading mood is a little different from the news broadcasting statements mood as usual, it is slower Thus the rhythm of a word including monosyllable is made
to a more prominent position and the prosody of them becomes the key prosody of Chinese poetry
We concentrate on the prosody between adjacent syllables in one word in Chinese poetry and propose a prosody module in section 3.2 and section 3.3
3 The Chinese Poetry Prosody Model
The Chinese poetry prosody mainly includes three levels, the syllable prosody, the word prosody and the sentence prosody
3.1 The Syllable Prosody
The pitch and duration are two important features in syllable prosody It is well known that Chinese is a tonal language, the tone represent the pitch in physics The tone is exits
on certain duration There are four lexical tones including tone1, tone2, tone3 and tone4
in Mandarin Chinese Chinese phonetist Yuanren Zhao had introduced a method called five-grade tone-marking [1] to describe the Chinese tones It gives the corresponding tone type for each lexical tone which conveys the pitch changing trends on certain duration of one syllable As figure 1 show, it divides the vertical pitch axis into five
1 2 3 4 5 Relative pitch
Duration
Relative ratio
1 0.841 0.707
1.189 1.414
Fig 1 Five-grade tone-marking
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levels The ratio between each adjacent level is 21/4 The five levels is a relative value If
we set level3’s value equals 1, the level2’s value can be calculated as 0.841 etc Then the tone1’s tone type is defined as “555” which means the relative pitch value at the start time, middle time and end time point on the duration of syllable, and we con-catenate the adjacent pitch point with a line In the same way tone2’s tone type is de-fined as “345”, tone3 as “214” and tone4 as “531” Once we give an absolute average pitch value of the syllable and a certain duration, we can calculate its pitch value of any time point in the duration by the module
3.2 The Word Prosody
The word prosody mainly includes tone changing and coarticulation [2]
Chinese word tone prosody is based on its character’s tone In continuous speech the syllable tones type maybe changed and no longer equal to its basic tone type For example, the word “慷慨” in spelling is “kang1kai3” whose tone combination is “1-3” and original tone type combination is “555-214”, but the tone type will be changed into
“555-21” which makes it sounds more natural by our Mandarin Chinese pronunciation custom We have experimented on all kinds of Chinese tone combinations and then give out the changed tone type combinations as table 1 shows
Table 1 Tone Changing
tone i-tone j 1sttonetype 2ndtonetype tone i-tone j 1st tone type 2nd tone type
The second feature of word prosody is coarticulation Coarticulation is a phe-nomenon happened when one syllable pronounce by the end with another syllable is about to start pronounce in a word, the latter syllable’s pronouncing way will affect the former one’s
How human voice produces? The principle is the airflow comes from our lung and through the glottis, if the vocal chords vibrate then the vowel formed, or else the con-sonant formed And the airflow continues to get through the vocal tract, which is