Malay Speech Corpus

Malay Speech Corpus CHAPTER 3 MALAY SPEECH CORPUS 3.1 Introduction The knowledge related to the structure of the rules and grammar for any language must be understood in depth prior to the development of any Automatic Speech Recognition (ASR) systems. This chapter is intended to discuss the related issues concerning the Malay language and its speech sounds.   The Malay corpus and the test collections used for this study are also presented in the following sections. 3.2Malay Speech Sounds and Language Rules Malay is an Austronesian language spoken by the Malay people who are native to the Malay Peninsula, southern Thailand, Singapore and parts of Sumatra and also known locally as Bahasa Melayu. It is the official language of Malaysia and is an agglutinative language, meaning that the meaning of the word can be changed by adding the necessary prefixes or suffixes that will be explained through out of this section. The smallest unit in any language is known as phoneme.   The substitution of this unit for another might make a distinction of meaning (Nong et al. 2001).   Integrating the phonemes produces the syllable and words.   Generally, phoneme classification for Malay language is divided into three major groups that consist of Vowels (V), Consonants (C) and other miscellaneous (Manaf Hamid 1996).   This structure is relatively same with the English language as shown in Figure 3.1 (Karim 1996). The vowel class comprises of six vowels that is: /a/, //, /i/, /o/, /u/ and /e/.   The vowel sound is produced when the air exit from the lunges and mouth without ant noise. The second category, which is consonant class, can be further divided into seven different categories that is the stops or plosive group, affricates, nasals, glides, liquids, fricatives and the semivowel.   The sounds from consonants are produced by air from lungs and consist of noise.   The noise is generated in mouth and nose, for instance, phoneme /p/and /b/.   Figure 3.2 describe the consonant utterances classification for the Malay language. The last category, miscellaneous category, consists of the diphthong and vowel functions.   Vowel function is a combination of two different vowel (ia, io and iu) and most often used in words absorbed directly from its English equivalent such as radio and audio, and in some original Malay words such as nyiur (coconut), hias (decorate) (Hussain, 1997). 3.2.1Malay morphology Malay morphology is defined as study of word structures in Malay language (Lutfi Abas, 1971). A morpheme is the term used in the morphology. A morpheme is the smallest meaningful unit in a language. In another words, morpheme is a combination of phonemes into a meaningful unit. A Malay word can be comprised of one or more morphemes. When we talk about Malay morphology, we cannot avoid from discussing the process of word formation in Malay language. It is a language of derivative which allows the addition of affixes to the base/root or primary word to form new words. The language itself is different from the English. In English language, the process involves the changes in the phonemes according to their groups. The processes of word formation in Malay language are in the forms of primary words, derivative words, compound words and reduplicative words. 3.2.1.1Primary word Primary or root words are either nouns or verbs, which is does not take any affixes or reduplication. A primary word can be comprised of one or more syllables. A syllable consists of a vowel (V) or a vowel with a consonant (C) or a vowel with several consonants. The vowel can be presented at the front or back of the consonants. In Malay language, primary word with one syllable accounts for about 500 only (Nik Safiah Karim et al. 1995). Some of the primary words are taken from other languages such as English and Arabic. The structures of the syllable are shown in Table 3.1. Primary words with two syllables are the majority in the Malay language. The structures of the words are shown in Table 3.2 with example of words that illustrated as in Figure 3.3. Primary words with three and more syllables exist in a few numbers. Most of them are taken from other languages as shown in Table 3.3. Table 3.1:   Structure of words with one syllable Syllable Structure Example of word CV Ya (yes) VC Am (common) CVC Sen (cent) CCVC Stor (store) CVCC Bank (bank) CCCV Skru (screw) CCCVC Skrip (script) Table 3.2:   Structure of words with two syllables Syllable Structure Example of word V + CV Ibu (mother) V + VC Air (water) V + CVC Ikan (fish) VC + CV Erti (meaning) VC + CVC Empat (four) CV + V Doa (pray) CV + VC Diam (silent) CV + CV Guru (teacher) CV + CVC Telur (egg) CVC + CV Lampu (lamp) CVC + CVC Jemput (invite) E R + T I V C + C V J E M + P U T C V C + C V C C Consonant V Vowel Table 3.3:   Structure of words with three syllables or more Syllable Structure Example of word CV + V + CV Siapa (who) CV + V + CVC Siasat (investigate) V + CV + V Usia (age) CV + CV + V Semua (all) CV + CV + VC Haluan (direction) CVC + CV + VC Berlian (diamond) V + CV + CV Utara (north) VC + CV + CV Isteri (wife) CV + CV + CV Budaya (culture) CVC + CVC + CV Sempurna (perfect) CVC + CV + CVC Matlamat (aim) CV + CV + VC + CV Keluarga (family) CV + CVC + CV + CV Peristiwa (event) CV + CV + V + CVC Mesyuarat (meeting) CV + CV + CV + CVC Munasabah (reasonable) V + CV + CVC + CV + CV Universiti (University) 3.2.1.2Derivative word Derivative words are the words that are formed by adding affixes to the primary words. The affixes can exist at the initial (Prefixes), within (Infixes) or final (Suffixes) of the words. They can also exist at the initial and final of the words at the same time. These kinds of affixes are called confixes. Examples of derivative words are â€Å"berjalan† (walking), â€Å"mempunyai† (having), â€Å"pakaian† (clothes) and so on. 3.2.1.3 Compound word Compound words are the words that are combined from two individual primary words, which carry certain meanings. There are quite lots of compound words in Malay language. Examples of compound words are â€Å"alat tulis† (stationery), â€Å"jalan raya† (road), â€Å"kapal terbang† (aeroplane), â€Å"Profesor Madya† (associate professor), â€Å"hak milik† (ownership), â€Å"pita suara† (vocal folds) and so on. Some of the Malay idioms are from the compound words such as â€Å"kaki ayam† (bare feet), â€Å"buah hati† (gift), â€Å"berat tangan† (lazy), â€Å"terima kasih† (thank you) and so on. 3.2.1.4 Reduplicative word Reduplicative words, as its name suggests, are the words that are reduplicated from the primary words. There are three forms of reduplication in Malay language: full, partial and rhythmic. Examples of reduplicative words are â€Å"mata-mata† (policeman), â€Å"sama-sama† (welcomed) and so on. 3.3Malay Speech Corpus Design Malay speech design basically involves the proper selection of speech target sounds for speech recognition.   The Malay phonemes can be analyzed according to the descriptive analysis and distinctive feature analysis.   Generally, the descriptive analysis is preferred over the distinctive feature analysis because it is easier to be implemented. To develop a baseline system for spoken Malay utterances or word model, we need database for isolated spoken Malay words.   However, very little of the literature and reference material in Malay is available in raw electronic form to support research and development work. These materials are sometimes not suitable for the real life speech recognition system due to their setting environments and most of these materials are recorded the planned or read text.Since no spoken Malay database exists, we develop the Malay corpus based on Hansard documents from Parliament of Malaysia. The hansard documents consists of Dewan Rakyat(DR)Parliamentary debates session for the year 2008.   It contains spontaneous and formally speeches and it is the daily records of the words spoken by 222 elected members of DR. The hansard documents comprises of 51 huge raw video and audio files (.avi form) of daily recorded parliamentary session and 42 text files (.pdf form). Each part of parliamentary session contains six to eight hours spoken speeches that surrounded with medium noise condition or environment (less than 30 dB), speakers interruption (Malay, Chinese and Indian) and different speaking styles (low, medium and high intonation or shouting).   The reason of chosen this kind of data is due to their spontaneous and natural way of speaking in a formal or standard Malay speech during the debates session. The analysis has been done to the whole recorded session from mid-term until the end 2008 of hansard documents. Out of 42 text documents and 51 video files, only 22 text documents and 22 video files were being selected due to their perfect matched in terms of the contents of video and audio source files. The remaining of the text documents and video files have not been chosen due to the missing of some text documents that could not be downloaded, some video files having corrupted during recording session and some of the recorded video having missed sounds.   This study focused and concerned to the video that have audio sounds since it will be used to develop the Malay corpus and to evaluate the performance of isolated spoken Malay speech recognition system. The quantitative information analysis, about the videos and text documents being selected is given in Table 3.4. Table 3.4: Quantitative information of Hansard documents selected. No. Video Text Documents No. of Topic No. of Speakers Total Words 1. DR28052008 (MEI) 11 129 40,283 2. DR29052008 (MEI) 15 114 39,612 3. DR24062008 (JUNE) 13 154 49,212 4. DR25062008 (JUNE) 10 118 38,053 5. DR30062008 (JUNE) 10 175 58,013 6. DR02072008 (JULY) 14 187 67,906 7. DR03072008 (JULY) 12 120 48,411 8. DR07072008 (JULY) 16 210 72,890 9. DR10072008 (JULY) 13 132 42,350 10. DR28082008 (AUGUST) 10 123 40,780 11. DR03112008 (NOVEMBER) 17 232 78,750 12. DR04112008 (NOVEMBER) 11 136 43,440 13. DR10112008 (NOVEMBER) 10 105 39,560 14. DR20112008 (NOVEMBER) 16 109 42,795 15. DR26112008 (NOVEMBER) 10 186 38,880 16. DR27112008 (NOVEMBER) 10 147 41,450 17. DR01122008 (DECEMBER) 7 118 38,430 18. DR02122008 (DECEMBER) 9 176 56,815 19. DR03122008 (DECEMBER) 12 152 48,616 20. DR04122008 (DECEMBER) 11 192 56,780 21. DR10122008 (DECEMBER) 6 130 38,677 22. DR11122008 (DECEMBER) 10 143 52,369 TOTAL The process of documents analysis shows that the majority of the Malay words are comprised of primary word with two syllables and mono (one) syllables. Among the Malay words, the syllables structure of VC, CV and CVC are the most common.   These structures are preferred because they are easy to be pronounced exactly as its written and their number is quite substantial in the hansard documents. In order to get a good distribution of consonants and vowels for the dataset from the hansard documents, the most frequently primary (root or base) words spoken by speakers during Parliamentary debates are used. As mentioned previously, most of the root words are the primary words that are either in nouns or verbs without adding any derivations (affixes and suffixes) or reduplication to the root words. Thus, from the text documents analysis, we determined 100 primaries words that mostly spoken by the committee members during the debates that consist of 10 primary words of one syllable, four p rimary words from three or more syllables structures and 86 primary words that form two syllables structures as depicted in Table 3.5. The details quantitative analysis of each words distribution is represented in Appendix A. Each primary word has maximum number of 50 repetitions that uttered by same or different speakers. Thus, there are a total of 5000 isolated spoken Malay words used for this research. The challenging task is to capturing and segmenting the exact words being uttered accordingly to the audio sounds in the video files. The process of creating isolated spoken Malay corpus is illustrated as in Figure 3.4 and briefly explained in the following sections. Table 3.2: Selection of 100 isolated spoken Malay words as the speech target sounds. No. Words Structures No. Words Structures 1 ADA V + CV 51 LAGI CV + CV 2 AHLI VC + CV 52 LAIN CV + VC 3 AKAN V + CVC 53 LAMA CV + CV 4 AKTA VC + CV 54 LANGKAH CVCC + CVC 5 ARAH V + CVC 55 LEBIH CV + CVC 6 ATAS V + CVC 56 MAKLUM CVC + CVC 7 ATAU V + CVV 57 MANA CV + CV 8 BAGI CV + CV 58 MASA CV + CV 9 BAIK CV + VC 59 MASIH CV + CVC 10 BAKAL CV + CVC 60 MESTI CVC + CV 11 BANK CVCC 61 MUNGKIN CVCC + CVC 12 BARU CV + CV 62 NANTI CVC + CV 13 BEKAS CV + CVC 63 OLEH V + CVC 14 BERI CV + CV 64 ORANG V + CVCC 15 BINCANG CVC + CVCC 65 PADA CV + CV 16 BOLEH CV + CVC 66 PIHAK CV + CVC 17 BUAT CV + VC 67 PRINSIP CCVC + CVC 18 BUKAN CV + CVC 68 PULA CV + CV 19 DALAM CV + CVC 69 PUN CVC 20 DAN CVC 70 RAMAI CV + CVV 21 DASAR CV + CVC 71 RIBU CV + CV 22 DATANG CV + CVCC 72 RUJUK CV + CVC 23 DENGAN CV + CCVC 73 SAH CVC 24 DIA CVV 74 SAMA CV + CV 25 EKONOMI V + CV + CV + CV 75 SANGAT CV + CCVC 26 ESOK V + CVC 76 SAYA CV + CV 27 HADIR CV + CVC 77 SEBAB CV + CVC 28 HAK CVC 78 SEBUT CV + CVC 29 HAL CVC 79 SEDANG CV + CVCC 30 HARI CV + CV 80 SEDIA CV + CVV 31 HENDAK CVC + CVC 81 SUDAH CV + CVC 32 IAITU VV + V + CV 82 SUSAH CV + CVC 33 IALAH VV + CVC 83 TADI CV + CV 34 INGAT VC + CVC 84 TAHU CV + CV 35 INGIN VC + CVC 85 TAHUN CV + CVC 36 INI V + CV 86 TIDAK CV + CVC 37 ISU V + CV 87 TANYA CV + CCV 38 ITU V + CV 88 TELAH CV + CVC 39 IZIN V + CVC 89 TENTANG CVC + CVCC 40 JADI CV + CV 90 TERIMA CV + CV + CV 41 JANGAN CV + CCVC 91 TIDAK CV + CVC 42 JAWAB CV + CVC 92 TIPU CV + CV 43 JUGA CV + CV 93 TUAN CV + VC 44 JUTA CV + CV 94