Transcript Phonetic Description of Speech Sounds

Sounds: the building blocks of
language
CA461 Speech Processing 1
Lecture 2
1
Building Blocks I
• Think of a word
• Write it down and read the word aloud
• Without looking at the word, write down
how many consonants and vowels are in
the word
• Do the same with the following words:
– Do, doo, red, read
• Do you notice anything?
2
Building Blocks II
• Now take all the words you have just
considered, say them aloud but don’t look
at their written forms, simply close your
eyes and concentrate on listening to the
words. Say them a number of times,
slowly if you like.
• How many distinct sounds make up the
words, do and doo?
• Our next aim is to describe these sounds
3
Phonetics: The Description of
Speech Sounds
•
•
•
•
•
Articulatory
Perceptual
Symbols
Acoustic
Will focus on acoustic description (next
lecture), but it useful to be familiar with
articulatory descriptions, symbols and
phonetic alphabets…
4
Articulatory Components
1. Vocal tract (filter)
– Oral, pharyngeal, nasal cavities
2. Glottis (glottal source)
– Space between vocals folds (cords)
– Located in larynx (voicebox)
– Anterior (front) of larynx is your Adam’s
apple
5
Vocal tract filter
Stylised
Mid-sagittal view
6
Nasal Cavity
Oral Cavity
Pharyngeal
Cavity
7
Larynx/Glottis
8
Consonant Classification
• Voicing/Phonation type
• Place of Articulation
• Manner of Production -- Degree of Stricture
• Velic Position
• Passage of airflow thru oral cavity
9
Voicing/Phonation type
• Voiced
– Glottis opens and closes rapidly
– Male ~100 Hz
– Female: ~200 Hz
• Voiceless/Unvoiced/Devoiced
– Glottis remains open
• Can you find voiced/voiceless pairs?
– Hint: Start with a voiced sound, e.g. [z]
10
Place of Articulation
• Main cavities for airflow
• Passive articulators
• Active articulators
– Primarily the tongue
11
Alveopalatal
Alveolar
Ridge
Palatal
Velum
Uvula
Lips
Epiglottis
Teeth
12
Manner of Production
(Degree of Stricture)
•
•
•
•
•
Stop/Plosive: complete closure
Fricative: close approximation
Approximant: open approximation
Trill
Affricate
13
Other
• Velic Position
– Nasal
• Passage of airflow thru oral cavity
– Central
– Lateral
14
3term labels
•
1.
2.
3.
4.
5.
•
For Example:
[ s ] Voiceless alveolar fricative
[ ʃ ] Voiceless alveopalatal fricative
[ m ] Voiced bilabial nasal stop
[ ŋ ] Voiced velar nasal stop
[ l ] Voiced lateral alveolar approximant
Notice the use of symbols
– Not all correspond to orthography
15
Vowel quality
• Shape of vocal tract tube
• Resonant frequencies -- formants
– Standing waves
– Tend to vary considerably
– Acoustics…next lecture
• Easier to use tongue and lip positions
16
Vowel Classification
by Tongue Position
• Locate
highest point
of normally
convex
surface
• Use vertical
and
horizontal
dimensions
Tongue
backness
Tongue
height
tongue
17
Vertical: Tongue Height
• 3 or 4 degrees:
–
–
–
–
close/high
closemid
openmid
open/low
• Puzzle: Order the vowels in the following words
in descending tongue height
–
–
–
–
Bed
Bayed
Bead
Bad
18
Horizontal: Tongue Backness
• 2 or 3 degrees:
– front
– back
– Central
• Puzzle: For each of the following pairs of
words which vowel is front/back?
– Head, hod
– Hood, hid
19
Vowel Classification contd...
• Lip Position
– Rounded
– Unrounded
• Puzzle: For the following pair of words
which vowel is Rounded/Unrounded?
– Reed, rude
• Finer distictions (eg. Swedish)
20
3term labels: Vowels
•
•
•
•
For Example:
[ i ] close front unrounded
[ ε ]openmid front unrounded
[ u ] close back rounded
21
Other ‘Dimensions’ for
Classification
•
•
•
•
•
•
Voiceless
Nasality
Retroflexion: rcolouring / rhotacisation
Tense vs. Lax
Length
Breathy vs.Creaky
22
Monophthongs vs. Diphthongs
• Monophthong
– Pure vowel
• Diphthong:
– rising/closing
– centring
– falling/opening
• Triphthong?
23
Cardinal vowels
• Primary cardinal vowels
• Secondary cardinal vowels
24
Phonetic Alphabets
•
•
•
•
•
IPA
Arpabet
Sampa
Worldbet
Exercise:
– Choose any word with more than 3 or more
syllables
– Phonetically transcribe it in IPA and one other
phonetic alphabet
25
Broad vs. Narrow Transcription
Phone Environment
Example
IPA
tʰaɪ
[t]
Syllable initial
After [ s ] or in
reduced syllables
[ʔ]
[ɾ]
Various
Between vowels
kʰɪʔn̩
bʌɾɚ
[t̚]
Before consonants
or word finally
Before dental
consonants
Word finally?
frut ̚kʰeɪk
[ tʰ ]
[ t̪ ]
[ ]
stɑrfɪʃ
eɪt̪θ
pʰæs
26
Next
• Acoustic phonetics
• Puzzle for later (after next 2 lectures):
– How does vowel height and backness relate
to the first two formants?
27