The 10-milion-words Spoken Dutch Corpus and its potential use in experimental phonetics

1. The 10-milion-words Spoken Dutch Corpus and its potential use in experimental phonetics Louis C.W. Pols Institute of Phonetic Sciences University of Amsterdam 100 Years of Experimental Phonetics in Russia St.-Petersburg State Univ., Febr. 1-4, 2001

2. Amsterdam city center Herengracht 338

3. Overview • Introduction • Corpus design, recording, digitization • Orthographic transcription • Part-of-speech tagging, lemmatization and syntactic annotation • Phonetic transcription • Prosodic transcription • Exploration • Potential phonetic benefit

4. Introduction • appropriate topic given long Russian tradition • Dutch-Flemish initiative • 10 Mƒ, 10 M words (about 1000 hrs of speech) • start June 1998, 5 yrs, 7 releases (audio + ann.) • many speaking styles, also over telephone, only adult speakers, ABN variants but no dialect • for linguistics and speech/language technology • rights with NTU (http://www.taalunie.nl)

5. Corpus design(number of words x 1000) dialogues and multilogues monologues

6. Recording, digitization • mono or stereo using portable DAT-recorders • 16 kHz and 16 bit (telephone recordings at 8 kHz and 8 bit) • .WAV format in PRAAT • meta data about recording and speaker • 7 audio releases on CD-ROM, or DVD (future?) • annotations updated with each release

7. Orthographic transcription (1) • by trained students, checked by expert • according to fixed protocol; no text interpretations • transcr. aligned at few sec. chunks; multiple tiers • few punctuations; capitals for names only • standard spelling conventions, checked vs. lexicon • special mark-up symbols: • *d dialect words; *z regionally accented words • *t interjection; *a truncated wrd; *u mispronunciation • *v foreign words; *n new words; *x hardly intelligible • ggg speaker sounds; xxx unintelligible word(part)(s)

8. Orthographic transcription (2)

9. Part-of-speech tagging • all words in the text automatically tagged • discontinuous verbs not recognized at this level • Dutch tag set with 10 major word classes (noun, adjective, verb, pronoun, article, numeral, preposition, adverb, conjunction, and interjection) • additional morpho-syntactic features per class (e.g., singular, dimunitive and neuter for nouns) • resulting in some 300 tags • self-learning automatic tagger (given context)

10. Lemmatization • all words autom. paired with base form (lemma) • verbs  infinitive (gedaan  doen) other forms  stem (vijfde  vijf) truncated forms  full forms (z’n  zijn) • base form must be an independently existing form (hersenen  hersen; meisje  meis) • discontinuous verbs and split prepositions are not recognized at this level (op...bellen; van...uit) • one and only one baseform per word (vliegen  verb vliegen, or noun vlieg, depending POS)

11. Broad phonetic transcription (1) • on 10% of the data (mainly dialogues) • hand correction of automatic phonetic transcription • across-word assimilation, levels of reduction? • use of extended SAMPA • within PRAAT • word level respected die ik wel vind dat ze kloppen  di k wEl fInt_tAt s@ klOp@ • no hand segmentation at phoneme level

12. Broad phonetic transcription (2)

13. Signal coupling, word alignment • the phonetically transcribed part (1 M words) will be automatically aligned at word level • using ASR techniques (forced alignment) • this word alignment will be hand corrected • pauses and noises will also be aligned • geminate plosives are aligned separately, others shared (komt terug  kom t erug; is zeker  isseker) • inserted phonemes are shared with neighbouring words (toen belde n ie naar huis  belden nie • all the rest may be automatically aligned only • few seconds chunks are always accessible

14. Syntactic annotation • 10% will be semi-automatically annotated • procedure still under developed • interactive annotation software from NEGRA project (Saarbrücken) will be used • taking into account idiosyncracies of speech, such as hesitations, false starts, clause extensions • functional information (dependency labels) • category information (in form of node labels)

15. Prosodic annotation • manually, on 250K words subset only • procedure still under development • prosodic markers in orthography • 1) prosodic boundaries long silences () phrase boundaries () other discontinuities, like (filled) pauses (%) • 2) prominence (^ before vowel in prominent syllable) sp. A: n^ee  Jan heeft n^egen % medailles  z^even medailles.  sp. B: z^even 

16. Exploration software • COREX tool under developed (Max Planck Inst.) • both locally and internet-based (Java) • 1) browser • 2) viewer for orthography and annotations, plus waveform display and audio player (time synchr.) • 3) search module, also on meta data

17. Potential phonetic benefit • huge database, many speakers/styles,‘real’ speech • easily accessible via orthography, plus audio • partly accessible via phonetic transcription • no segmentation at phoneme level (automatic?) • automatic segmentation at word level • after COREX search: own additions possible • f.i. spectro-temporal analyses via PRAAT scripts • f.i. svarabhakti vowel, final n-deletion, assimilation • f.i. vowel reduction, turn-taking behavior, etc.

18. More information • see references in paper • see websites mentioned in paper • second release Oct. 2000 • new releases every half year • feedback from users group (workshops) • useful for proposed INTAS project “Spontaneous speech of typologically unrelated languages (Russian, Finnish and Dutch): Comparison of phonetic properties” (De Silva, 2000)