Speech Classification Speech Lab Spring 2009 February 17, 09 1 Montgomery College Speech Classification Uche O. Abanulo Physics, Engineering And Geosciences

Speech Classification Speech Lab Spring 2009 February 17, 09 2 Montgomery College Detailed Classification PhonemesPhonemes VowelsSemivowelsConsonants Transitionals Glides Liquids Fricatives Nasals Plosives Whispers AffricatesDiphthongs

Speech Classification Speech Lab Spring 2009 February 17, 09 3 Montgomery College Speech Production System

Speech Classification Speech Lab Spring 2009 February 17, 09 4 Montgomery College Vowels Source – –Quasi-periodic puffs of airflow through the vocal folds vibrating at a certain fundamental frequency, which is the pitch System – –The formation of each vowel depends on the vocal tract configuration, which depends on the following factors: The tongue – position and degree of constriction Lips – degree of openness, roundedness Jaws Examples – –/a/ in father – tongue is raised at the front, low degree of constriction of tongue against palate – –/i/ in eve - tongue is raised at the front, high degree of constriction of tongue against palate

Speech Classification Speech Lab Spring 2009 February 17, 09 5 Montgomery College Vowels VowelExample ieve Iit eHate aFather call oobey Ufoot uboot Aup Rbird

Speech Classification Speech Lab Spring 2009 February 17, 09 6 Montgomery College Fricatives Source – –Noise generated buy some turbulent airflow along the oral tract System – –The formation of each fricative depends on If the vocal tract is vibrating or not (for voice and unvoiced fricatives) the tongue Lips Teeth – –There’s usually a voiced/unvoiced pair Examples – –/z/ in Zebra – vocal folds vibrate along with noise production – –/s/ in sweet – No vibration along with noise production

Speech Classification Speech Lab Spring 2009 February 17, 09 7 Montgomery College Vowels Voiced FricativeExampleUnvoiced Fricative Example vvoteffor DthenTthin ZazureSshe zzoossee

Speech Classification Speech Lab Spring 2009 February 17, 09 8 Montgomery College Nasals Source – –Quasi-periodic airflow from vibrating vocal folds System – –Air flows through the nasal cavity, sound is radiated at the nostrils – –Sound is determined by the position of the tongue’s constriction Examples – –/m/ in Man – tongue’s constriction is at the lips – –/n/ in No – tongue’s constriction is at the gum ridge – –/G/ in sing – tongue’s constriction is near the velum

Speech Classification Speech Lab Spring 2009 February 17, 09 9 Montgomery College Plosives Source/System – –Burst generated as a result of pressure build-up behind an oral tract contriction Oral tract is initially closed (with vibration of vocal cords for voiced plosives and no vibration for unvoiced plosives) Release of air pressure and generation of turbulence over a very short duration Examples – –/g/ in go – vibration occurs along with constriction – –/k/ in baker – no vibration occurs along with constriction

Speech Classification Speech Lab Spring 2009 February 17, Montgomery College Whispers Source – –Noise generated buy some turbulent airflow along the oral tract System – –No constriction of oral tract but no vibration either – –aspiration Examples – –/h/ in he

Speech Classification Speech Lab Spring 2009 February 17, Montgomery College Transitionals Diphthongs – –Vocal tract moves between two vowel sounds – –e.g /Y/ in hide; /W/ in out; /O/ in boy; /JU/ in new Affricates – –Formed by the transition from plosive to fricative – –Example /ts/ in chew – transition from /t/ to /S/; /J/ in just – transition from /d/ to /Z/

Speech Classification Speech Lab Spring 2009 February 17, Montgomery College Semi-vowels Voice-like in nature Glides – –Dynamic and transitional – –Very similar to diphthongs – –Usually occur between two vowels or before a vowel – –More constriction of oral tract during transition than diphthongs – –Greater speed of oral tract movement – –e.g: /w/ in away and /y/ in you Liquids – –Similar to glides except for the tongue constriction – –e.g. /l/ in liquid, /r/ in right

Speech Classification Speech Lab Spring 2009 February 17, Montgomery College Why Speech Classification Artificial speech production Speech correction Speech recognition

Speech Classification Speech Lab Spring 2009 February 17, Montgomery College Generalized speech classification VoicedVoiced  Quasi-periodic excitation  Modulation by vocal tract  Production of vowels, voiced fricatives & plosives UnvoicedUnvoiced  No periodic vibration of vocal chords  Noise-like nature  Production of unvoiced fricatives and plosives

Speech Classification Speech Lab Spring 2009 February 17, Montgomery College Generalized speech classification

Speech Classification Speech Lab Spring 2009 February 17, Montgomery College Generalized speech classification

Speech Classification Speech Lab Spring 2009 February 17, Montgomery College Lab – simple observation 1. 1.Record yourself saying /S/ as in shout 2. 2.Read and plot your file 3. 3.Repeat 1 and 2 above with the phoneme /a/ as in father. Now let’s compare the two figures

Speech Classification Speech Lab Spring 2009 February 17, Montgomery College Lab – more detailed 1. 1.Record yourself saying shout Now we’ll work together to create a voiced unvoiced detection system using only energy.

Speech Classification Speech Lab Spring 2009 February 17, Montgomery College Group Project 1. 1.Record yourself saying supercalifragilisticexpialidocious 2. 2.Manually label your recording as voiced/unvoiced 3. 3.Automatically label your recording using the speech classification system we just created 4. 4.Compare your manual and automatic labels Figures will be awesome 5. 5.Discuss all the different phonemes contained in the recorded word including 1. 1.What kind of phoneme are they? 2. 2.How are they produced? 3. 3.Are they voiced or unvoiced? more??? 6. 6.One-two page report due next week.

Speech Classification Speech Lab Spring 2009 February 17, Montgomery College Research 1. 1.Research on different ways for classifying speech into phonemes or as voiced/unvoiced other than energy Each group will give a 10 minute presentation at the next meeting