Week 6 - Consonants

Mark Huckvale

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Last Week

• Vowels may be described in terms of phonology, phonetics, acoustics and audition.

• There are about 20 phonological choices for vowels in English. • The Cardinal Vowel system can be used to describe the quality of

any vowel in any language. • Vowel quality can be described using terms such as front-back,

open-close, rounded-unrounded, short-long, monophthong-diphthong.

• The source-filter model of vowel production explains the acoustic form of vowels

• The frequency response of the vocal tract pipe used for vowels can be characterised using the frequencies of the first few formants.

• Formant frequencies for a given phonological vowel vary across speakers, even of the "same" articulation.

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Consonantal Choices

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Minimal Pairs

• pin, bin, din, tin, kin, gin, chin

• coat, goat

• sum, sun, sung

• whip, rip, lip, yip

• fin, thin, sin, shin

• vat, that, hat

• baize, beige

• pass, parse

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Consonant Choices in English

• pen, spin, tip • but, web • two, sting, bet • do, odd • cat, kill, skin, queen, thick • go, get, beg • fool, enough, leaf • voice, have, of • thing, breath • this, breathe • see, city, pass • zoo, rose • she, sure, emotion, leash • pleasure, beige • ham

• chair, nature, teach • gin, joy, edge • man, ham • no, tin • singer, ring • left, bell • run, very • we • yes • what (some accents, e.g. Scottish) • loch (Scottish)

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Place of Articulation

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Place

Place Articulation

Bilabial Both lips

Labiodental Lower lip and upper teeth

Dental Tongue tip and teeth

Alveolar Tongue tip on teeth ridge

Palatal Tongue blade on hard palate

Velar Tongue body on soft palate

Glottal Vocal folds in larynx

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Manner of Articulation

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Manner

Manner Articulation

Plosives Complete obstruction, explosive release

Nasals Complete obstruction, nasal port open

Affricates Complete obstruction, fricative release

Fricatives Partial obstruction causing turbulence

Approximants No obstruction

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Voicing

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Voice

Voice Articulation

Voiced Vocal fold vibration, or rapid restart of vibration at plosive release

Voiceless No vocal fold vibration, or delayed restart of vibration at plosive release

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Voicing Changes

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Phonetics of English Consonants

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Bilabial Alveolar Velar

Voiced Plosive bin b din d give g

Voiceless Plosive pin p tin t kin k

Nasal sum m sun n sung ŋ

Plosives & Nasals

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Fricatives & Affricates

Labiodental Dental Alveolar Palato-alveolar

Glottal

Voiced Fricative

vim v this ð zing z measure ʒ

Voiceless Fricative

fin f thin θ sin s shin ʃ hit h

Voiced Affricate

gin dʒ

Voiceless Affricate

chin tʃ

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Approximants

Labial-velar Alveolar-retroflex

Alveolar-lateral

Palatal

Voiced wasp w wrong r long l yacht j

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Consonant Acoustics

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Acoustics of Approximants

Approximant articulations create vocal tract tubes similar to vowels and their acoustics are thus also similar to vowels

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Frequency Frequency Frequency

Am

plit

ud

e

Res

po

nse

Am

plit

ud

e

Source Filter Vowel

Vowel Acoustics

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Spectrograms

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j w

l r

Acoustics of Nasals

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Vocal Tract Tube for Nasals

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Spectrograms

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m n ŋ

Acoustics of Fricatives

Fricative articulations create a narrow constriction at some point along the vocal tract tube. Turbulence is generated at the constriction and shaped largely by the tube forward of the

constriction.

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Laminar & Turbulent Flow

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Low fluid velocity

High fluid velocity

Vocal Tract Tube for Fricatives

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Shadle 1990

Frequency Frequency Frequency

Am

plit

ud

e

Res

po

nse

Am

plit

ud

e

Source Filter Fricative

Fricative Acoustics

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Frequency Frequency Frequency

Am

plit

ud

e

Res

po

nse

Am

plit

ud

e

Source Filter Fricative

Fricative Acoustics

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5 10 15 20

-10

010

20

30

40

50

/h/

Channel

Energ

y (

dB

)

5 10 15 20

-10

010

20

30

40

50

/ʃ/

Channel

Energ

y (

dB

)

5 10 15 20

-10

010

20

30

40

50

/s/

Channel

Energ

y (

dB

)

5 10 15 20

-10

010

20

30

40

50

/θ/

Channel

Energ

y (

dB

)

5 10 15 20

-10

010

20

30

40

50

/f/

Channel

Energ

y (

dB

)

Average fricative spectra 0-10kHz

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h ʃ s

θ f

Fricative Place

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f s

θ ʃ

h

Fricative Voicing

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s z

Acoustics of Plosives

Plosives have a closing phase, closed phase and release phase. At release a short burst of turbulence occurs which is shaped by adjacent vocal tract cavity resonances.

p t k

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Plosive Voicing

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b p

Freq

Time

F2

F1

vowel transition stop-gap

burst

transition vowel

[b] = voiced, unaspirated

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Weak larynx buzz dying out

[ph] = voiceless, aspirated

Freq

Time

F2

F1

vowel transition stop-gap

burst

transition vowel

Aspiration

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Plosive Place

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b d g

Place cues to plosives include: spectral shape of burst and movements of formants going into and out of stop

Summary

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Summary

• Phonological choices can be determined by finding minimal pairs

• There are about 24 consonant choices in English which can be classified according to their typical articulation

• Consonants are described using the Voice-Place-Manner system

• Approximants and Nasals have similar acoustics to vowels

• The source of energy for fricatives is turbulence generated at or near the constriction. Fricative spectra vary according to size of cavity forward of the constriction

• Plosives have a series of events: closing, hold, burst, opening, and optional aspiration. Place cues for plosive are related to the spectrum of the burst and the formant transitions

• Voice Onset Time is an important voicing cue for plosives

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PALS1004 Remaining Sessions

Lectures

Mon 19 Feb – Lecture

Mon 26 Feb – No lecture

Mon 5 Mar – No lecture

Mon 12 Mar – No lecture

Mon 19 Mar - Lecture

Laboratory classes

Wed 21 Feb – Lab class

Wed 28 Feb – Lab class

Wed 7 Mar – Lab class

Wed 14 Mar – Lab class

Wed 21 Mar – Lab class

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Course handouts and lecture slides will be available on Moodle as usual