Distinctive features of Speech Sounds

1. DISTINCTIVE FEATURES

2. Distinctive Features- different
systems and implications
 Phoneme----basic sound unit of a
language
 Each language has a finite set of
them.
 Eg: English: 45 phonemes
 The phoneme is produced by a set of
articulatory and phonetic maneuvers
that have distinct articulatory and
acoustic properties.

3.  Therefore phonemes are a bundle of
articulatory and acoustic features.
 Linguists have attempted to device a
set of universal phonetic features
called distinctive features that may be
used to analyze the sounds in all the
world language into units smaller than
the phoneme.

4.  These DF are the ‘atomic’ constituents
of sound segments that cannot be
broken down any further
(Jackobson’49)

5.  Distinctive Feature theory---- R–
Jakobson (1940)
 Over the years many different
Df system have been developed.

6. In DFs,
Each feature
a switch
Either present/
absent
(+/_)

7. Each sound
A unique set
of features
No two sound segments, by
definition, may have exactly
the same set of features.
The term binary is used in most distinctive
features analyses to indicate the similarities and
differences between sound segments

8. Eg: /k/ vs /g/
/k/ /g/
 + consonantal
 - vocalic
 - voice
 + consonantal
 - vocalic
 + voice
Voicing is the only feature that distinguishes
/k/ from/g/.

9. Most of the DF systems
proposed Binary
Peter Ladefoged (‘71.’93) Multivalued
features.

10.  Eg of multivalued features includes
using 1,2,3,4, to distinguish b/w
differences in vowel height. Thus [æᵆ]
is considered 1, while [i] is 4
(Ladefoged, 93)

11. DF systems by various
researchers
 Consonant Feature systems:
 Jakobson, Fant and Halle (1951)- this
method of analysis was based on
acoustic features, mostly utilizing the
spectrographic representations of
sounds and proposed 12 binary
universal features. However only 8/12
features were used to describe 21 Eng
consonants.

12. 1) vocalic/non vocalic- all vowels and
semivowels are vocalic and is marked
by the voice source.
 Can be represented on a spectrogram
by clear formants in the lower 1/3rd of
the speech frequency region.
 All consonants except/l/ are non
vocalic

13. 2) consonantal/ non consonantal:
 Opp of vocalic/ non vocalic feature
 Ie, non vocalic are consonantal and
vocalic are non consonantal.
 All consonants of English are non
consonantal, except /h/. All vowels are
non consonantal.

14. 3) compact/ diffuse: the basic
distinction between the compact and
diffuse features is in terms of the
location of the energy. Ie the
frequency regions of the speech
sounds.
 Compactness
 diffuseness
The concentration of energy in one
central frequency region
Trace of one or more frequency
concentration in the non central (ie
low or high or both) frequency region

15. 4) grave/ acute: diffuse consonants
with energy concentrated in the upper
portion of the speech frequency region
are called acute.
 Diffuse consonants with energy
concentrated in the lower portions of
the speech frequency region are
called grave.
 /p, b, f, v, m/ are grave consonants.
 /t,d,r,s,z,n/ are acute consonants.

16. 5) nasal/ oral:
nasal
Narrow band of energy at
a very low frequency
(approx 200Hz)
(/m,n,ŋ/
Nasal resonance
Oral
consonants
Relatively high energy
at 2500 Hz.
All other consonants except
/l/ and /h/ are oral where
primary resonating cavity is
the oral cavity

17. 6) tense/ lax: tense consonants have
larger duration and greater strength of
explosion than lax counterparts.
/p,t,k/ are tense where as /b,d, g/ are
lax. Voiced are lax and voiceless are
tense./h/ does not have a lax counter
part.

18. 7) continuant/ Interrupted- considered as
envelope feature. Therefore there is
smooth envelope of energy or smooth
onset of energy for continuant
consonants and an abrupt envelope of
energy for interrupted consonants.
 The continuant consonants are /f,
v,s,z,∫,Ɵ,Ʒ/
 Interrupted consonants are /
p,t,k,b,d,g,ʧ,ʤ/
 These features do not apply for /m,n,ŋ,
l,h/. All fricatives are continuants and all
oral stops and affricates are interupted.

19. 8) strident/ Mellow: sounds with
irregular or random ditribution of
waveform are considered strident
eg:/s/. And sounds with relatively more
regular wave form distribution are
mellow sounds.
/ʧ, ʤ, s,z/ are srtident and /k,g,--, --/ are
mellow in the original JFH system.

20. Miller & Nicely (1955)
 Five feature system
 Voicing, duration, affrication, place
and nasality.
 The five feature included 4 articulatory
and one acoustic feature.
 They designated 1 to a consonant
having a feature and 0 to a consonant
not having a feature.

21. 1. voicing: differentiated vd/vless
Voiced 1
Voiceless 0

22. 2. Duration:
 Primarily an acoustic feature.
 Fricatives /s, z, ʃ, ʒ/ have4 greaeter
duration than other fricatives and sets
them apart.

23. 3) Affrication: the closure is such that
at the point of contact air is forced
through a ……… aperture (in the
shape of a slit or a groove), the result
is a kind of turbulence or a fricative
that distinguishes / ,Ɵ,s,ʃ,v, ,z,Ʒ/ from
/p,t,k,b,d,g,m,n/

24. 4) Place of articulation: specification for
place of articulation are Front, medial
and back depending on the position in
the oral cavity where the construction is
formed. If constriction is in the front of
the oral cavity, the designation is place-0
(p,b,v,m)
A construction in the middle of the mouth
is considered place- 1 (/t,d,s,z,n,ɵ/
Constriction in the back of the mouth is
place - 2 (k,g, ʃ,Ʒ)

25. 5) nasality: the nasal consonants are
produced by opening the
nasopharyngeal port and releasing the
intra oral air pressure through the
nose.

26. 3. Singh & Black (1966)
 Extended the Miller & Nicely feature
system by adding
1. Liquid (to distinguish /b/ from /w/ and
/g/ from /j/.
2. Retroflexion
3. A fourth value to the place feature, to
distinguish /ʧ/ from /h/.

27. 1. Front (p, b, m, f, v)
2. Mid front (t, d, s, z, Ɵ,…, l, n)
3. Mid back (ʃ, ʒ, ʧ, ʤ, r)
4. Back (k, g, h)

28.  In 1968, Singh and Black further
extended the system to include 8
features of which 7 were binary namely,
 Voicing, nasality, fricative, duration,
liquid, glide, retroflex.
 And one was quaternary, namely the
place of articulation feature.
 Singh’s feature system is more
complete.
 Therefore it distinguishes all (25)
consonants of English from one another.

29. Implications of DF
 DF’s can be applied in describing the
phonological development of a child,
in ascertaining the magnitude of the
articulatory problems and also in
impacting therapy to articulatory
deviant children.

30.  Menyuk (‘68) studied the rank order of
Dfs acquisition during phonological
development in American and
Japanese children.
 She found that the rank order of
features was identical in these
languages.
 Prather et al (’75) studied the art devpt
in children from 24 to 48 months in
terms of Df of consonants.

31. In evaluation of Speech
 DF s systems offered several
advantages over the previous analysis
system of classifying errors according
to substitutions, deletions and
distortions.

32.  For eg. In the instance of the
substitution of /p, t,k/ for /b,d,g/, it may
not be sensible to say that the child
has a /b/ problem, /g/ or /d/ pb.
 Actually the child does not have 3
different problems, rather he has only
one problem---the voicing feature has
been errored.

33.  Therefore DF analysis contrasted the
feature of the target sound to the
substitution. The end product was a
list of Dfs that differentiated b/w the
target and the substitution. This
analysis could show whether
 1. error and target sounds shared
common features
 2. specific error patterns existed

34.  Therapeutic implications follow logically. If the
child can be taught to differentiate b/w the
presence and absence of these differentiating
DFs, the error sounds should be easily
remediated.
 According to Jakobson(‘42/’68) , if children
acquire features rather than sounds, a certain
amount of generalization should occur.
 i.e a child who can produce + voicing in one
phoneme context should be able to
generalize this + voicing to other phoneme
context.

35.  This would be treating more than one
phoneme in more efficient manner.
 However both the analysis procedures
and the clinical applicability of DF for
speech disordered children have been
questioned by several authors. Some
comments are that DFs are abstract
concepts