Speech Suprsegmentals- Rhythm and Its Importance

1. RHYTHM

2. Two ways of defining Temporal characteristics of a
spoken utterance.,
1)Tempo 2) Rhythm
Tempo is the rate at c utterance is spoken.
Rhythm of an utterance is the pattern of time
intervals c elapse b/w occurrences of stressed
syllables.
The term ‘Rhythm ‘is derived from the Greek word
‘Rhuthmos’ where ‘Rhu’means flow.

3. Rhythm is defined as a pattern of movement C
occurs on more or less with temporal regularity.
It is a certain swing or balance in bodily movt,
Music, verb or phrase.
In Sanskrit literature, ‘Rhythm’ is a nature of time.
It means metrical movts. (eg., clock)

4. • Unit /ta:la/ is measure for rhythm.
• Music has regular rhythm
- Music has a regular rhythm,
- Eg., 1) sa, ri, ga, ma, pa,da, ni, sa
2) Ba, Ba, Black ship

5. SPEECH RHYTHM
Some rhythm exist in Sp, but not regular
Rhythm gives a shape to a sentence, an idea of
length of a sentence & Melody.
It also marks the beginning and end of a Phrase.
It helps in memorizing a particular prose Or poetry
and leads to ease of pronunciation.
• Fairbanks (1945): Rhythm is sp pattern of vocal
change which is inherent in sp or draws attention
to the need for breathing pattern which underlies
pause, stress, rate, pitch & intensity.

6. Speech rhythm…. CONTD
Rhythm in Sp is special in 2 ways.
Firstly, it is not strictly regular beat
Tempo & rhythm changes during utterances in
relation to wd & clause boundaries.
If there is no rhythm, Sp breaks down leading to
‘dysprosodia’.
The sense of rhythm is not properly developed or
is disrupted in HI,STTG,CLTTG dysarthria,
apraxia and aphasia {Stark weather, 1987}
.

7. Measure of rhythm
• Feet: a measure of rhythm, distance b/n
successive stressed syllable.
• Metrical feet: rhythmic structure of poetry &
suggests that systematic relationship b/n ft &
rhythm persists.
• 1 syllable foot: 1 foot (stress on all syllables)
• 2 syllable foot: 2 foot
• Foot: includes syllable/ single wrd/ diff wrds.

8. Functions of rhythm
Rhythm tends to promote / enhance fluency
Rhythm assists in rapid sp prodn
Aids to anticipate up coming movts.
Important perceptual cue for the recognition of
meaningful stimulus.
The movement of the listeners tend to be in
synchrony with syllabic rhythm of sp produced by
speaker.

9. Rhythmic patterns
Classified as.,
1)fast
2)Slow
Fast rhythm: we hear it as a whole. A machine
gun is a fast sd, we can hardly count its beat.
Slow rhythm: we can hear each beat separately.
Eg., hand clapping for music.

10. Types of rhythm in language
If a lang has simple syllabic structure, for eg,
VC(eg., at), or CCV (eg., cry) the durational
difference b/n syllabic structures is not wide.
duration of syllabic structure--- < 330ms
under these circumstances, we use a fast syllable
timed rhythm.
If the syllable is still simpler, for eg., VC or CV
then the durational diff b/n syllables is
negligible. ------ such lang is mora-timed lang

11. If a lang has complex syllabic structure, for eg, V &
CCCVCC the durational difference b/n syllabic
structures is very wide.
For eg., duration of V (eg., I)--- 60 ms, duration of
CCCVCCC (eg., strength) is >600ms.
under these circumstances, we use a slow stress
timed rhythm.
The rhythm class hypothesis states that each lang
belongs to one of the prototypical Rhythm.

12. Ramus, Nespor & Mehler(1999) measured
consonant & vowel intervals in 8
languages(England, Dutch, French, Polish,
Spanish, Italian, Catalan, Japanese).
Results:
Percentage of vowels & consonants provided
best acoustic correlates of rhythm.
Vocalic Intervals (VI) was smaller and
consonant intervals (CI)was greater in English
compared to other languages.
This reflected that English has more complex
syllable options.

13. On the basis of VI,CI ,classifies
England, Dutch, Polish,
________ stress timed language.
French, Spanish, Italian, Catalan
________ syllable timed language
Japanese
________ Mora timed language.

14. Eg, occurrence of syllables
English
Unifom ------- VCVCVC
Butiful --------- CVCVCVC
BUK --------- CVC
Kannada
Pustaka------- CVCCVCV
Nanu----- CVCV

15. English V/s Kannada
English: has word final consonants
Kannada: word has to end in a vowel.
The type of syllables in English r more
complicated than in Kannada.
Consonant Interval is higher in English compared
to Kannada.

16. Pair wise variability Index (PVI)
Grabe and Low (2002) calculated PVI across
languages.
PVI : calculation of successive vocalic and
intervocalic interval pattern.
Based on PVI.,
England, Dutch, Germany – as stress timed
language
French, Spanish - as syllable timed language
Japanese - as mora timed language

17. Inter vocalic interval (IVI)
vocalic interval(VI-vowel duration)
IVI VI
Stress timed language High High
Syllable language High Low
Mora language Low Low

18. Measurement of rhythm--- production
Record sp sample
tap for rhythm
indicate the taps on a transcribed materials.
Sp samples of Normals can be compared with
that of clinical population for production of
rhythm.
Acoustically , measure Fo, duration, intensity
of the tapped syllable.
Acoustic measures in clinical popn can be
compared to that of normals.
Pair wise variability index can b measured.

19. Measurement of rhythm--- speech perception
Rhythm can be simulated or recorded music can
be played
Participant r instructed to tap for the rhythm
heard.
Acoustically analyzed for correct perception of
ta:la, duration b/n taps and reaction time.
Same procedure can be used for training to
perceive
Rhythm by providing the visual cues of tap by
clinician
high lighting auditorily change in rhythmic pattern.

20. Indian studies
Savithri, Jayram, kedaranth & Goswami (2006)
investigated rhythm in Hindi & Kannada
language
Reading and spoken lg was recorded and
analyzed for PVI.
Results:
Hindi ----syllable timed language
Kannada----- mora timed language.

21. To summarize concepts on rhythm
measurement,
 initially concept of Isochrony (syll hs equal
duration) was noted
Followed by vowel duration, % vocalic &
consonant intervals.
Finally PVI used
however there r still unclassified lgs . Therefore
there might b much more than PVI.

22. Indian studies
• Balasubramaniam (1980)
• Rhythm in tamil lang
• Results: Tamil is neither a stress timed nor a
syllable timed lang
• Why not stress timed lang?
• Stressed syllable do not tend to occur at
regular intervals of time
• Why tamil is not syllable timed lang?
• Syllables do not occur at regular intervals of
time

23. Indian studies
• What is Stress timed lang?
it takes one unit of time to utter 1 unstressed
syllable b/n 2 successive stressed syllables,
3/4/5 unstressed syllable b/n 2 successive
stressed syllables,
• Should take the same unit of time
• Stress is not present as above in tamil lg,
hence its not a stress timed lg.

24. Indian stu
• Savithri (1991)
• Rhythm in Kannada
• Results: 2 feet occurred maximally followed
by 3 feet & 1 foot.
• Stress after 2 syllables.
• Eg., ˈnanu ˈi:ga barˈti:ni

25. • Savithri & Rashmi (1992)
• Rhythm pattern in Kannada
• Stimuli: 65 Kannada sentences depicting various
emotions– audio recorded
• Beats were identified by Kannada spkrs on the
basis of stress patterns.
• Results: no specific rhythmic pattern in Kannada,
& no foot pattern. Of all positions final position
were maximally stressed.
• Martin (1984): Syllable/ stress timing is a vague
notion & rhythm prones to be a misnomer.

26. Development of Rhythm
Several authors suggested tat rhythm of very
young children is syllable timed.
polysyllabic utterances of young child are
compared of reduplicated forms ( eg., pumjum
for pyjamas)
It includes short sequences of phonologically
similar and unreduced monosyllables.
By the age of 4 or 5 the rhythm becomes more
adult like.

27. Atkinson & King (1973)
Several studies indicate that the segmental
timing shows a devtl trend in children and that
children start to develop Sp rhythm as early as
15 months, C is continuous till age of 12 years.

28. • 18-36 months - lacks normal rhythm - unable
to imitate sentences (Eilers, 1975)
• By 2 yrs (Hawkins et al,1980) - speech rhythm
has fewer syllables per foot & so it sounds
more syllable timed since early utterances r
composed of largely reduplication of syllables.
• Syllables are deleted by 2-3 yr olds in 2
phonetic environments,
- word initial
- next to unstressed syllable (Hawkins, 1979)
4-7 yrs, followed after 14 mnths, found
durational devtl trends were evident as age

29. • The very 1st word children produce do not
show as much stress contrast as in adult speech
(Ingram et al,1974)
• 2 syllable word containing stressed and
unstressed syllable are typically produced as if
they were spondees
• The only indication of stress is in the raised Fo
of the stressed syllable
• Sounds in the unstressed syllable may be lost,
and instead the child produces adjacent, stress
syllable (“ray-ray for raisin”)

30. Dissimoni(1974)
• Avg duration of vowels & consonants↓ as age ↑
• Suggests child’s accuracy & ability to control
timing of sp improves with age.
• Yairi (1981): children start acquiring sp rhythm by
the age of 2-3 yrs & then it develops upto age of
8 yrs.

31. Models of Rhythm: Three models
1.Comb model (Kozhevnikov & Chistovich, 1965)
2.Chain Model (Kozhevnikov & Chistovich, 1965)
3.Isochrony Model (Abercrombie, 1965)

32. Comb Model
- According to this model, the units of sp are
executed according to some underlying
Programmed time schedule.
- Pre programming is similar to open-loop
control
B1
B2 B3

33. - the control exercised in the system, does not
rely on the o/p (feedback).
- Preprogramming may also be defined as a set
of commands that are structured
Before a movement sequence begins and that
allows the entire sequence to be
Carried out, uninfluenced by peripheral fd back
(Keele, 1968)

34. Chain Model
there is no underlying time program or rhythm.
-A given SP gesture, simply is executed after the
preceeding gestures have been
Completed successfully.
B1
B1
B2
B2
B3
B3

35. - A chaining strategy for motor sequencing
assumes that the performance of any
of a series of movements depend, upon fd
back, regarding the accomplishment of
a preceding movement.

36. Isochrony Model
• ‘Isochrony’ refers to the phenomenon.
• In a stressed timed language Ex: English,
Stressed syllables follow each other at
approximately equal time intervals.
• In the isochronous foot model, the first syllable
in each foot is a stressed syllable,
• If the model is correct, the durn of every foot
will be equal.
• The rhythm of an utterance is the pattern of
time intervals which elapse b/n the Occurrence
of stressed syllables.

37. Two Types of rhythmic patterns are found in
isochrony.
1.Stress timed isochrony
2.Syllable timed isochrony
In stress timed lg the stressed syllables follow
each other at approximately equal time
intervals
Eg: S1’ S2 S3 S4’ S5 S6 Eg., English
T1 T2
If, T1 = T2, (T=Time) = 500 ms, (S=Syllable)
Stress will occur for every 500 ms

38. In syllable timed languages, the syllables follow
each other at regular time intervals, Eg:
French .,Eg: S1’, S2, S3’, S4, S5’, S6,
concept of foot in rhythm
1 Foot - stress occurs on all syllables - S1’, S2’,
S3’, S4’
2 Foot - Stress occurs on alternate syll - S1’, S2,
S3’, S4
3 Foot - Every 3rd
syll is stressed - S1’, S2, S3, S4’,
S5, S6,S7’
4 Foot - Every 4th
syll is stressed - S1’, S2, S3, S4,
S5’, S6, S7,S8

39. 5 Foot -Every 5th
syll is stressed - S1’, S2, S3, S4,
S5, S6’, S7,S8,S9, s10
6 Foot –Every 6th
syll is stressed - S1’, S2, S3, S4,
S5, S6, S7’,S8,S9, S10,
S11,
S12
In Sp it occurs up to 6 feet & occurrence of 7-12
feet is very rare.

40. Tests of Rhythm
The Tennessee test of rhythm and inton
patterns (T-trip)
Developed by Koike & Asp (1981).
3 parts, 1-17 Test items,
Part 1 & 2 : tests for rhythm, part 3 : test for
intonation
Nonsense syllable / ma/ spoken & recorded with
different rhythm and inton patterns.

41. - Musical notations were used to indicate the
appropriate tempo.
- The rhythmical patterns had 2 levels of stress
(stressed or unstressed) & two levels of tempo
(regular or quick) for each syllable.
- Since stressed syllable usually have a higher
pitch, the stressed syllable was designated as
high pitch (top line) & unstressed syllable as
mid pitch (mid line)
- Each syllable was identified by a single dot
(large dot- stressed, small dot- unstressed)

42. For part I, the rhythm section – Test items 1-14,
had 2-6 syllables(/ma/) varied in stress and
tempo.
In Part II:- Items 15,16 & 17
The tempo ed 1-3 syllables / beat & this
produced 3-9 syllables .
- children (3 years & 5 years) imitated the pattern
- Results: 5 years old scored significantly better
than 3 years old.
- The T-Trip test appears to be sensitive to
differentiate b/n grps of different ages.

43. -
Figures depict the rhythm part of the T-Trip test.
1 7
Big dot: stressed, small dot: unstressed,
top line: high pitch, mid line: mid pitch,
baseline: low
Regular, quick, pause----- pattern

44. Synthetic test of rhythm (Jayanthi Ray, 1993)
17 synthetic stimuli varying in Fo, intensity and
duration.
Part 1, 2 & 3
In part 1, 6 stimuli with change in Fo ( increase
in steps of 10 hz) keeping intensity and
duration as constant were prepared.
In part 2, 6 stimuli with change in intensity (in
steps of 10 dB steps) keeping fq and duration
as constant.
In part 3, 5 stimuli with change in duration ( in
10 ms steps) keeping fq and intensity as

45. Synthetic test of rhythm….. contd
• These stimuli were given for imitation by
adults and children.
• Results indicated,
Adults cud imitate 1 ft to 4 feet, had difficulty
in imitating 5 ft & 6 ft.
Stimuli with intensity & Fo changes
(individually) were better imitated than
duration.
Devtl trend ws indicated in children

46. Synthetic test of rhythm……contd
• This test can b used as clinical tool to explore
suprasegmental functioning in persons with
dysprosodia.
• Therapeutic tool to facilitate rhythmic sp
• To enhance sp intelligibility in persons with
arhythmia.

47. Rhythm in Normals
The discontinuity in Normal speakers r likely
to occur at syntactic location where lang is
being formulated.

48. Rhythm in sttg
• Starkweather & Gordon (1983): Sttg & other
discontinuities r likely to occur at syntactic
locations were lang is being formulated.
• Physiological weakness of coordination in spkg
• Results in as lack of fluency--- slow rate,
repeated elements, hesitation, unusual amt of
effort in spkg.
• Hence, disfluency is a sign of temporal
incoordination.

49. Implications to Tx
With additional information on rhythm, focus
on rhythm is possible.
For eg., if a language is stress timed, a stress
timed approach to teach rhythm is appropriate.
If a language is mora timed, then a mora timed
approach is appropriate
Prolonged sp techniques r based on the idea of
equal syllable timing.
If a language is stressed timed language,
prolonged sp techniques may not be
appropriate.