Speech Classification Speech Lab Spring 2009 February 17, 09 1 Montgomery College Speech...

Speech Classification Speech Lab Spring 2009

February 17, 09February 17, 0911

Montgomery Montgomery CollegeCollege

Speech ClassificationSpeech Classification

Uche O. AbanuloPhysics, Engineering

And Geosciences




Detailed ClassificationDetailed Classification

PhonemesPhonemesPhonemesPhonemes

VowelsVowelsVowelsVowels SemivowelsSemivowelsSemivowelsSemivowels ConsonantsConsonantsConsonantsConsonants TransitionalsTransitionalsTransitionalsTransitionals

GlidesGlidesLiquidsLiquids

FricativesFricativesNasalsNasals

PlosivesPlosivesWhispersWhispers

AffricatesAffricatesDiphthongsDiphthongs




Speech Production SystemSpeech Production System




VowelsVowels

• 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




VowelsVowels

Vowel Example

i eve

I it

e Hate

E Met

@ at

a Father

c all

o obey

U foot

u boot

A up

R bird




FricativesFricatives

• 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




VowelsVowels

Voiced Fricative Example Unvoiced Fricative

Example

v vote f for

D then T thin

Z azure S she

z zoo s see




NasalsNasals

• 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




PlosivesPlosives

• 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




WhispersWhispers

• 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




TransitionalsTransitionals

• 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/




Semi-vowelsSemi-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




Why Speech ClassificationWhy Speech Classification

• Artificial speech production• Speech correction• Speech recognition




Generalized speech classificationGeneralized speech classification

• VoicedVoiced

Quasi-periodic excitationQuasi-periodic excitation

Modulation by vocal tractModulation by vocal tract

Production of vowels, voicedProduction of vowels, voiced fricatives & plosivesfricatives & plosives

• UnvoicedUnvoiced

No periodic vibration of vocal No periodic vibration of vocal chordschords

Noise-like natureNoise-like nature

Production of unvoiced Production of unvoiced fricatives and plosivesfricatives and plosives





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Embedded Voiced Speech

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Embedded Unvoiced Speech





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An Unvoiced Segment from a Male Speech Signal




Lab – simple observationLab – simple observation

1. Record yourself saying /S/ as in shout2. Read and plot your file3. Repeat 1 and 2 above with the

phoneme /a/ as in father.

Now let’s compare the two figures




Lab – more detailed Lab – more detailed

1. Record yourself saying shout

Now we’ll work together to create a voiced unvoiced detection system using only energy.




Group ProjectGroup Project

1. Record yourself saying supercalifragilisticexpialidocious

2. Manually label your recording as voiced/unvoiced3. Automatically label your recording using the speech

classification system we just created4. Compare your manual and automatic labels

• Figures will be awesome

5. Discuss all the different phonemes contained in the recorded word including

1. What kind of phoneme are they?2. How are they produced?3. Are they voiced or unvoiced?4. more???

6. One-two page report due next week.




ResearchResearch

1. Research on different ways for classifying speech into phonemes or as voiced/unvoiced other than energy.

2. Each group will give a 10 minute presentation at the next meeting

Speech Classification Speech Lab Spring 2009 February 17, 09 1 Montgomery College Speech...

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