Spraakherkenning en -synthese

Transcription

1 Spraakherkenning en -synthese 1 1 Phonetic Sciences University of Amsterdam january, 2014 (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185 Outline 1 Administrativa 2 The sound chain Phonetics and phonology Speech Hearing (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185

2 Administrativa Administrativa Classes: Monday, Tuesday, Wednesday, Friday 11-13, at varying locations Practicum: Monday, Tuesday, Wednesday, Friday 13-17, 9-13 at varying locations Assignments have to be fulllled to enter the exam Deliver assignments via BlackBoard Tentamen: Friday January 31, Hertentamen:?? SHS website: Software: Praat on Linux, Windows, MacOs (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185 Administrativa Outline of this course : Impressionistic classication, IPA Speech organs Characteristics: pitch, spectrum, spectrogram, LPC, formants Speech synthesis Formant synthesis Speech recognition Markov models (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185

3 The sound chain The sound chain Intention of speaker (higher centers of brain) Language (phonetic, intonational, and durational form) Motor program and muscle movement (diaphragm, larynx, tongue, jaw, lips,...) Sound wave in air (vibrations radiate through air) (Electronic transduction) Hearing (eardrums waves: tympanum membrane) mechanical motion:ossicles uid pressure waves: basiliar membrane rings in 30,000 neural bers: auditory nerve) Auditory and language processing (lower centers of brainstem, thalamus, auditory cortex, and language centers cooperate meaning + emotional state, and intention in speaking) Understanding (higher centers of the brain) (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185 The sound chain Phonetics and phonology Phonetics and phonology Phonetics Physics of speaking, sound, and hearing Production, signal characteristics, dierences... Sound systems Phonology: Sound systems Vowel and consonant system: Phones & Phonemes phone is a basic speech sound phoneme is a set of phones of the same class allophone variant of a phoneme (Dutch r's) Allowed combinations: Phonotactics Sound changes: Assimilation & Coarticulation "handbag" is often pronounced hambag "tuinbank" as tuimbank ProsodyProsody Phonetic reps: [A] Phonological reps: /A/ (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185

4 The sound chain Parts involved in speaking Speech (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185 The sound chain Speech Sound production Human voiced sound production: Air pressure from lungs creates steady ow of air through trachea (windpipe), larynx (voice box) and pharynx (back of throat) Vocal folds in larynx vibrate, creating uctuations in air pressure that are known as sound waves Resonances in vocal tract modify these waves according to position and shape of the lips, jaw, tongue, soft palate, and other speech organs, creating formant regions and thus dierent qualities of sonorant (voiced) sound Mouth and nose openings radiate sound waves into environment (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185

5 The sound chain Speech Source-lter model of speech production Source-lter model of speech production models a speech sound as a combination of a sound source and a linear acoustic lter. Speech sound has a source which is ltered by the vocal tract The source can be: glottal vibrations, airow noise from a constriction, or a combination of both, a trill... The lter is the complete oral and/or nasal cavities or the part following a constriction It can in general be assumed that source and lter act independently The ear (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185 The sound chain Hearing (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185

6 Basic speech sounds The sound chain Dit is zichtbaar gemaakte spraak Two categories 1 Vowels Hardly any constriction in the vocal tract Examples: o, e, i, u, a... 2 Consonants Constriction in the vocal tract Examples: p, k, l, m,... (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185 The sound chain Consonant classication Three features 1 Manner of articulation (sound source) Fricative, plosive, nasal,... 2 Place of articulation (lter shape) Constriction at the lips, teeth, alveolar ridge, palate... 3 Voicing Vibrating vocal folds or not (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185

7 Manner of articulation The sound chain Nasals; m, n Lowered velum makes air escape through the nose Plosive: p, t, k,... Complete closure, pressure building up, release Fricative: f, s,... Almost complete closure, friction Approximant: Dutch: weer articulators approach without turbulent airow. Trill, Spanish: perro, French: garçon vibrations between the articulator and the place of articulation Tap, Flap: latter single contraction of the muscles so that one articulator (such as the tongue) is thrown against another Laterals (fricative, approximant, ap) ; l el-like: airstream along sides of tongue (blocked from going through middle of mouth) (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185 The sound chain Other manner of articulation terms Sibilants Manner of articulation of fricative and aricate consonants, made by directing a stream of air with the tongue towards the sharp edge of the teeth, which are held close together. Examples of sibilants are the consonants at the beginning of the English words sip, zip, ship, chip, and jeep, and the second consonant in vision Aricates Consonants that begin as stops but release as a fricative. E.g. Eng: chip, jeep Liquids: Class of consonants consisting of lateral consonants together with rhotics. Rhotics: R-like sounds (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185

8 The sound chain Place of articulation Labial: b Both lips (bilabial) Lower lip and the upper teeth (labiodental) Dental:d Tongue against the upper teeth Alveolar: s Tongue against or close to the superior alveolar ridge Palatal: j Body of the tongue raised against the hard palate Velar: k Back part of the tongue (the dorsum) against the soft palate Uvular: huig-r Back of the tongue against or near the uvula Glottal: h Consonants articulated with the glottis (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185 The sound chain Other place terms Coronal: articulated with exible front part of tongue Dental+alveolar: that, zoo, name, lift Dorsal: articulated with the mid body of the tongue Velar+uvular: Garden (Eng) (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185

9 IPA notation The sound chain Standardized by International Phonetic Association (IPA) Publishes the International Phonetic Alphabet IPA: character representation of all sounds of all the world's languages Latin alphabet: /m/, /n/, /o/,... Turned or inverted characters: /6/, /ô/,... Diacritics: /p'/ Greek alphabet, /E/ New shapes resembling existing characters: /ï/, /ñ/, /N/,... (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185 The sound chain Pulmonic consonants Pulmonic sounds originate from air from the lungs egressive (created by exhaling, majority of sounds) ingressive (created by inhaling) (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185

10 The sound chain Non-pulmonic consonants Voicing (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185 The sound chain Voiced: b, d, g Voiceless: p, t, k (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185

11 Dutch consonants The sound chain Plosive p b t d k g paal baal taal dop kok goal Fricative f v s z S Z x G fiets vies sier zier sjaal rouge acht gele Nasal m n ñ N maar naar oranje ring Liquid l leuk ô ter Aricate V j week jeuk (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185 The sound chain Dutch vowel system i y I Y e ø E a u o O A Where symbols appear in pairs, the one on the right is rounded. Diphthongs: /Au/, /œy/ and/ei/ (Phonetic Sciences UniversitySpraakherkenning of Amsterdam) en -synthese january, / 185