Do older adults experience changes in their speech fluency? Some evidence from Iranian elderly people

Original Article
Masoome Samani1,Fateme Abnavi2,*Leila Ghasisin2
1Student Research committee, Isfahan University of Medical Sciences, Isfahan, Iran
2Communication Disorders Research Center, Rehabilitation Sciences Institute, Isfahan University of Medical Sciences, Isfahan, Iran
DOI:http://dx.doi.org/10.24816/jcgg.2017.v8i4.05

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Abstract

Background

Normal aging can affect speech fluency. Changes in anatomy and physiology of speech production system in elderly people may reduce speech fluency. However, few studies have been conducted on age-related changes in speech fluency and their results are very contradictory. The aim of this study was to explore speech fluency characteristics in elderly adults and to respond to controversies in this field.

Methods

For this purpose, speech fluency features of 32 young adults, 37 middle-aged adults, 33 young-old adults and 26 old-old adults in conversation were analyzed. Speech and articulation rate, frequency and duration of pauses and frequency and type of disfluencies were calculated.

Results

The findings showed that speech rate, frequency of other disfluencies (OD) and frequency of pauses in young adults were significantly different with young-old and old-old adults. The same significant differences were found between middle-age adults and both young-old and old-old groups. In terms of articulation rate, frequency of stuttering-like disfluencies (SLD) and duration of pause, there was a significant difference between old-old group and other age groups.

Conclusions

Changes in cognitive capacity, anatomy and physiology of speech production system affect the speech fluency in elderly people. Therefore, aging would affect speech fluency even in normal elderly people.

Keywords

articulation rate, elderly people, speech fluency, speech rate, pause

Article Outline

  1. Introduction
  2. Methods
  3. Results
  4. Discussion
  5. Limitations
  6. Conclusions
  7. Conflict of interest statement
  8. Funding Statement
  9. References

Abstract

Background

Normal aging can affect speech fluency. Changes in anatomy and physiology of speech production system in elderly people may reduce speech fluency. However, few studies have been conducted on age-related changes in speech fluency and their results are very contradictory. The aim of this study was to explore speech fluency characteristics in elderly adults and to respond to controversies in this field.

Methods

For this purpose, speech fluency features of 32 young adults, 37 middle-aged adults, 33 young-old adults and 26 old-old adults in conversation were analyzed. Speech and articulation rate, frequency and duration of pauses and frequency and type of disfluencies were calculated.

Results

The findings showed that speech rate, frequency of other disfluencies (OD) and frequency of pauses in young adults were significantly different with young-old and old-old adults. The same significant differences were found between middle-age adults and both young-old and old-old groups. In terms of articulation rate, frequency of stuttering-like disfluencies (SLD) and duration of pause, there was a significant difference between old-old group and other age groups.

Conclusions

Changes in cognitive capacity, anatomy and physiology of speech production system affect the speech fluency in elderly people. Therefore, aging would affect speech fluency even in normal elderly people.

Keywords:

articulation rate, elderly people, speech fluency, speech rate, pause

1. Introduction

Changes in speech production are expected through aging. Speech is a dynamic phenomenon requiring rapid interactions of planning processes and muscle movements.1 Respiration, phonation, articulation, and resonance subsystems must work harmoniously to produce speech.2 Speech is affected by changes in anatomy and physiology of speech production system, sensory feedbacks, motor control, and central processing of speech in older adults.3 Kent argues that changes in precision and fluency of speech and voice which occur through aging affect communication.4 In older adults, changes that occur in the mechanism of speech production can make conversation difficult and reduce fluency of speech.5

Fluency of speech involves a soft, gentle, and continued flow that can change by various factors such as speech rate, pauses, hesitation, interjection, repetitions, prolongation, and revision.6

Speech rate is a supra-segmental feature of speech that has been used to define speech fluency. This feature is a speech motor function that reflects coordination among subsystems of speech. Speech rate includes two parts: (a) the rate of producing speech units, and (b) duration of pauses between words. On the other hand, articulation rate is how fast articulators work during speech production. This is a temporal feature of speech, and reflects motor transferability irrespective of disfluencies and pauses, as well as timing aspects of speech motor control.7 Because articulation rate does not include pauses, hesitations, emotional expressions and other unique features of the speaker to transfer information; it shows the actual rate at which speech units are produced, better than speech rate.8

Previous studies in the area of speech changes in older adults have led to highly contradictory results. A study by Duchin and Mysak on young adult (21-30 years), middle aged (44-54 and 55-64) and older males (75-91), which included reading the first paragraph of the text of “Rainbow”, describing a picture, and conversational speech showed that speech rate was higher in young adults compared to the middle-aged and middle-aged compared to older adults, but no difference was observed in frequency of disfluencies.9 Leeper and Culatta reported that there were no changes in the frequency of disfluencies among young adults (25-34 years) and older adults (55-85 years).10 In their study, Shewan and Henderson showed decreased speech rate through aging, but the decrease was not significant, and they also reported no significant difference in the frequency of disfluencies.11

In contrast, a study by Yairi and Clifton on spontaneous speech in non-stuttering age groups of preschool children, high school seniors, and geriatric people showed that not only did preschool children and older adults have similar disfluency patterns, but also they showed greater frequency of disfluencies than high school seniors.12 A study by Andrade and Martin on 60-69 years, 70-79 years, 80-89 years, and 90-99 years age groups showed that disfluency occurs more in older adults due to higher frequency and duration of pauses, and their speech rate decreases.6

A number of studies have highlighted the difference in speech after the age of 80. For instance, Andrade and Martin showed greater influence of age on speech fluency parameters after the age of 80.6

Few studies have been conducted on speech articulation rate in older adults. A study by Jacewicz et al. conducted on 20 to 34-year-old and 51 to 65-year-old age groups in two different regions in America showed that younger adults had higher articulation rate compared to older adults.13 A study by Bona on 20 to 32-year-old and 66 to 90-year-old age groups showed that age affected speech rate, articulation rate, and frequency of pauses.14

Several studies have emphasized the need for further collection of data on speech changes in elderly people. Such data can provide an insight into speech parameters in aging.15On the other hand, greater attention has been paid to speech production ability in elderly people suffering from neurological damages. However, very few studies have investigated the normal effect of aging on speech production skills in elderly persons. Moreover, many of the studies conducted on speech in elderly adults related to their voice, and very few have investigated motor control in speech.

1.1. The Current Study

As the first study of its kind in the Persian language, this study aims to provide further information on the relationship between aging and speech changes for which very contradictory findings have been reported, and to find relevant information in Persian speaking older adults. There is a growing population of older people in Iran. According to the 2012 census, 8.2% of the population of Iran is over 60 years old. According to the International estimates, population of older people in Iran will grow faster by 2033, and will exceed the mean global growth rate by 2045.16 Because of the increasing population of older people, speech-language pathologists should have sufficient knowledge about changes in speech that happen through aging, so that they can distinguish between normal age-related changes in speech and disfluency associated with common diseases in elderly population. The quality of life and speech characteristics begin to be affected through aging.17 Voice and speech are considered as the most important tools for daily communication and are integral to people’s personality, hence contributing to their overall goodness and quality of life.18 Oral communication forms the basis for various activities of daily living ranging from the maintenance of social and personal relationships to the fulfillment of routine needs. Adequate communication skills including speaking, listening, reading and writing have a critical role in obtaining of health care services. Studies have shown that the quality of life correlates more closely with health condition in the elderly. Social communication can affect personal health condition. Although alternations in communication skills may occur gradually, they can result in such consequences as withdrawal from social context and situations.19

Communication can also be viewed as a means of achieving autonomy, which may become vulnerable in older people. The interrelationship between communication and autonomy necessitates speech-language pathologists and other health-care professionals paying attention to communicative peculiarities of senior citizens.6 Moreover, as a member of the treatment management team, they should also be familiar with features of speech in older people, so that they can contribute toward providing appropriate services to improve their quality of life. Hence, the results of this study can provide speech-language pathologists with the knowledge of changes in speech in aging.

2. Methods

This article was extracted from the Master’s thesis entitled “study of impact of aging on temporal characteristics of speech”. The thesis has been reviewed and approved scientifically by the research council of Isfahan university of medical sciences (registration code: 394435), beside the whole procedure was approved by Ethics Committee of Isfahan University of Medical Sciences (Ethics code: 394435).

2.1. Participants

Thirty-two young adults (M age = 36.81, SD: 6.21, range 20-44 years old), 37 middle aged adults (M age = 52.43, SD: 11.4, range 45-59 years old), 33 young old adults (M age = 68.11, SD: 5.14, range 60-74 years old) and 26 old-old adults (M age = 86.12, SD: 6.84, range 75-90 years old) voluntarily participated. All participants were Persian-speaking people with no history of speech-language disorders, stroke or brain traumas, depression, cognitive or mental problems, with normal hearing.

Old adults were referred from the center of geriatrics of Isfahan. These old people get periodic checkups for their physical and mental health at this center and the assessment of their health records are recorded. After getting satisfaction from volunteers, their medical records were studied carefully. Then those who were cognitively and mentally healthy and had no difficulties affecting speech features were included in the study. Written consent was obtained from them again. Young adults and middle aged adults were chosen from students, staff, and professors of Isfahan University of Medical Sciences through an announcement and their health and safety were assessed through health questionnaires.20

2.2. Procedures and Measures

Speech sample was obtained through spontaneous conversation about the same subject for all participants, who were required to introduce themselves and talk about their families at normal speed and loudness. Participants were tested individually. Speech samples were recorded using a mouthpiece microphone (Headset Acorn HS50 model) with the sensitivity of: 105dB±3dB, at 2.5cm distance from mouth 8, and the software Praat (5.3) at 44,100 Hz/sec. Participants were able to design their speech contents and language form, and were allowed sufficient time to talk without interruption. Prior to the tests, sufficient explanations were provided, and participants were familiarized with the test procedure. The first 5 minutes of participants’ speech were analyzed.14

After recording samples, varieties of disfluencies were identified in two groups, including stuttering-like disfluencies (SLD), such as syllable repetition, sound repetition, prolongation, blocks, pauses, and intrusion of sounds or segments, and other disfluencies (OD) including hesitation, interjection, revision, non-finished words, word repetition, and segment repetition or phrase repetition.6 Then, frequency of various disfluencies (number of disfluencies in 100 words) was calculated. Since pause as a speech temporal feature would affect speech and articulation rates,14 frequency and duration of pauses were also calculated. Pauses lasting longer than 200 milliseconds were calculated.21 The number of syllables was calculated according to number of vowels through PRAAT Script, and speech rate was found by dividing the number of syllables by total speech time (including pauses) and articulation rate was found by dividing the total number of syllables by total speech time (without pauses).14

The inter-reliability was determined by two researchers analyzing 10% of speech samples from each age group, and inter-agreement exceeded 92% in all calculated parameters. Two months after initial analysis, intra-reliability was determined by random selection and analysis of 10% of speech samples from each age group by the first researcher, and intra-agreement was greater than 95% in all calculated parameters.

Statistical analyses were performed using one-way ANOVA, and Tukey post hoc test at the 95% confidence level.

3. Results

Table 1 and Figure 1 show mean and standard deviation of speech and articulation rates, duration and frequency of pauses, and OD and SLD disfluencies in different age groups in conversational speech. Speech rate and articulation rate, duration and frequency of pauses, and OD and SLD disfluencies were compared using ANOVA test, and then Tukey post hoc test was used to compare age groups.

3.1. Frequency of SLD

The one-way ANOVA showed a difference between various age groups in frequency of SLD (Table 1). The Post hoc test showed that only old-old group was significantly different from other groups in terms of frequency of SLD (P<0.05).

3.2. Frequency of OD

The one-way ANOVA showed a significant difference between different age groups in terms of frequency of OD (Table 1). The post hoc test showed that young-adult group was significantly different from young-old, and old-old groups in frequency of OD (P<0.05). There was also a significant difference between middle-age group and young-old and old-old age groups in frequency of OD. The same difference in frequency of OD was found between young-old and old-old groups (P<0.05).

3.3. Speech Rate

The one-way ANOVA showed a difference between age groups in terms of speech rate (Table 1). The post hoc test showed a significant difference between young-adult group and young-old and old-old age groups in terms of speech rate. Also, speech rate was significantly different between middle-age group and young-old and old-old age groups (P<0.05). The same difference in speech rate was found between young-old and old-old groups (P<0.05).

3.4. Articulation Rate

The one-way ANOVA showed a difference between age groups in articulation rate (Table 1). The post hoc test showed a significant difference only between old-old group with other age groups.

3.5. Duration of Pauses

The one-way ANOVA showed a difference between various age groups in duration of pauses (Table 1) and Post hoc test showed that only duration of pauses in old-old group was significantly different from other age groups (P<0.05).

3.6. Frequency of Pauses

The one-way ANOVA showed a difference between various age groups in terms of frequency of pauses (Table1). The Post hoc test showed that frequency of pauses in young adults was significantly different from young-old and old-old age groups (P<0.05). Moreover, frequency of pauses in middle-age group was significantly different from young-old and old-old age groups (P<0.05). The same difference in frequency of pause was found between young-old and old-old groups (P<0.05).

4. Discussion

This study aimed to investigate the effects of age on speech fluency. The obtained results showed that speech fluency is affected by increasing age. Furthermore, speech rate and articulation rate decrease and disfluencies increase in older adults.

Table 1. Summary statistics of the variables of the speech fluency profile for age groups

young adult middle age young old Old-old Anova young adult

vs.

middle age

 

young adult

vs.

young old

young adult

vs.

Old-old

middle age

vs.

young old

middle age

vs.

Old-old

young old

vs.

Old-old

Mean(SD) Mean(SD) Mean(SD) Mean(SD) F

(3, 122)

P Mean diff

(SD)

P Mean diff (SD) P Mean diff (SD) P Mean diff (SD) P Mean diff (SD) P Mean diff

(SD)

P
Frequency of SLD 17.9(2.8) 18.03(2.7) 18.45(4.5) 25(4.8) 2.24 <0.001 -3.93(1.55) 0.11 -5.7(1/56) 0.06 -10.66(1.79) <0.001 -3.78(1.6) 0.08 -8.65(1.23) 0.002 -8.75(1.64) 0.04
Frequency of OD 4.23(1.9) 4.45(2.1) 6.18(2.3) 8.94(3.1) 1.11 0.003 -1.5(0.69) 0.12 -2.49(0.71) 0.004 -3.71(0.75) <0.001 -4.96(0.69) 0.03 -2.45(0.73) 0.01 -2.18(0.63) 0.02
Speech rate (syllables/s) 5.13(0.67) 5.2(5.4) 3.31(0.54) 2.08(1.04) 2.24 0.04 0.106(0.16) 0.91 1.33(0.15) <0.001

 

1.44(0.16) <0.001 0.52(0.14) 0.004 0.62(0.15) 0.001 0.81(0.14) 0.03
Articulation  rate(syllables/s) 5.39(0.63) 5.02(0.75) 4.98(0.63) 3.52(0.87) 12.45 <0.001 0.40(1.58) 0.06 0.54(1.06) 0.07 -0.41(0.17) 0.002 0.13(0.15) 0.08 -0.81(0.16) <0.001 -0.95(0.17) <0.001
Duration of 

pauses    (ms)

398(169) 404(398) 440(252) 606(162) 0.97 <0.001 -1.15(0.45) 0.06 1.02(0.47) 0.08 -3.17(0.49) <0.001

 

-1.5(0.45) 0.1 -2.02(0.47) <0.001 -1.97(0.49) 0.02
Frequency of pauses 13.97(5.9) 14(4.7) 19.81(7.1) 23.6(7.6) 0.97 0.03 2.9(1.27) 0.1 -9.51(1.3) <0.001

 

-12.89(1.39) <0.001 -3.60(1.28) 0.03 -6.99(1.34) <0.001 -4.98(1.4) 0.03

 

The obtained results are supported by previous studies6,8,14,22,23 that showed speech and articulation rates decrease and duration and frequency of pauses increase through aging.

Zellner argued that continuous speech cannot occur in normal people due to physiological factors such as respiration and cognitive planning.24 Accordingly, it seems that continuous speech decreases in older people more than younger people. One of the reasons for increased frequency and duration of pauses, and the subsequent reduced fluency of speech through aging is considered to be a decrease in processing speed. Decreased processing speed may lead to poorer encoding and reduced ability to store data, which leads to difficulty in retrieval of words. Although this may happen at any age; word-retrieval difficulty appears to increase through aging. These difficulties can present as a variety of disfluencies, especially pauses, which ultimately lead to reduced fluency in older adults. Pause is a temporal feature speech, which can cause discontinuation of flow of speech, and show difficulty in word retrieval.14 Duration of pauses indicates the length of time needed to replan speech, 25 increased pauses lead to reduced rate of speech. In other words, pauses create an opportunity for speech processing in elderly people.

The internal control of articulatory timing is another reason for reduced speech rate,26 since these timing changes through aging, lead to reduced speech rate. Older people take more care in monitoring their speech compared to young people, and this reduces their speech rate. Sluggish neuromuscular and cognitive activities through aging can also lead to reduced speech rate and articulation rate.27 Goozee et al. showed that older adults are slower in articulatory movements than the younger adults.28 These results indicate motor control function, and also that older adults may show reduced neuro-sensory and motor function. 27 The present study results also suggest reduction in motor control function in older adults, and these changes were greater in old-old group compared to young-old, which showed greater effect of age on fluency in old-old group compared to other groups.

On the other hand, physiological conditions and neuromuscular system become weaker through aging. 29,30 Atrophy and fibrosis of the tongue muscle reduces muscle strength and regular and rhythmic movements of the tongue, and ultimately affect speech rate. Reduced neurotransmission speed in neuro-peripheral system, and reduced central neurotransmitters also reduce speech rate. 31Since it does not include pauses, articulation rate reflects the actual production rate of speech segments better, which does not include data transmission methods that are speaker-specific, such as pauses, hesitations, or emotional expressions, etc. In this study, articulation rate reduced through aging, which showed changes in speech motor control through aging.

Changes in cognitive capacity in old age should also be taken into account. Cognitive capacities affect motor behaviors. 4 These changes also appear to affect speech fluency features in elderly people.

As the age increases, there are some changes in cognitive capacities like memory and speed of process. This reduce helps the required time for processing and integrating information for motor programming to increase which caused longer time needed for old adults to start the movements such as motor speech. This can be the reason why pause and disfluency increase in old adults.32,33

Another factor affecting speech fluency is a reduction in lung volume. Even in healthy old adults, lung function reduces. Loss of elasticity in the respiratory system can lead to reduce in power in this system and the speaker’s need to have more effort to talk. As a result of a reduction in lung volume, the speaker sets his or her speech function to have less number of syllables every time he or she breathes and more pauses which lead to an increase in disfluency. 34

Fig. 1

Changes in SLD, OD, speech rate, articulation rate, duration of pauses and frequency of pauses in decade life

5. Limitations

This study is a cross-sectional one. Longitudinal studies are recommended to be done in this area. Participants in this study were those old adults referred from the center of geriatrics; therefore, the old adults registered in this center were the only subjects of our study which can affect generalizing the results. Conversational speech was studied in this paper in which the results cannot be generalized to other modalities like reading.

6. Conclusions

The present study results support the idea that increasing age affects fluency of speech. Changes in speech fluency can be expected even in normal old people without neurological or other disorders, due to changes in cognitive skills and capacities, and also due to anatomical and physiological changes, as normal outcomes of aging.

According to the results of this study and other related studies, it seems that regardless of age and language, as the age increases, speech rate and articulation decrease, whereas frequency of pauses and following that non fluency increase. As every language has its own unique features, and lingual, accentual, and geographical variants affect the speech and articulation rate and also the fluency, therefore, languages need to have to have their own standard data.

Conflict of interest statement

All authors have no conflicts of interest to declare.

Funding Statement

This article is extracted from a thesis for Masters by Masoome Samani registered at Isfahan University of Medical Sciences. This work was supported by the Isfahan University of Medical Sciences (Research cod: 394435).

Acknowledgement

We express our thanks to the subjects who volunteered to take part in this study and to Dr Hamid Karimi for his advice.

References

  1. Don S, Lickley R. Uh I forgot what I was going to say: How memory affects fluency. The 7th Workshop on Disfluency in Spontaneous Speech; 2015 August.
  2. Thelen E, Smith LB. Dynamic systems theory; in Damon W, Lerner RM (ed): Handbook of child psychology: Theoretical models of human development;2006, p. 258-312.
  3. Torre III P, Barlow JA. Age-related changes in acoustic characteristics of adult speech. J Commun Disord 2009; 42:324-33.
  4. Kent RD. Research on speech motor control and its disorders: A review and prospective. J of Commun Disord 2000;33:391-428.
  5. Bortfeld H, Leon SD, Bloom JE, Schober MF, Brennan SE. Disfluency rates in conversation: Effects of age, relationship, topic, role, and gender. Lang speech 2001;44:123- 47.
  6. Andrade CRF, Martins VO. Speech fluency variation in elderly (original title: Variação da fluência da fala em idosos). Pro Fono 2010;22:13-18.
  7. Chon H, Sawyer J, Ambrose NG. Differences of articulation rate and utterance length in fluent and disfluent utterances of preschool children who stutter. J Commun Disord 2012;45:455-67.
  8. Jacewicz E, Fox RA. Between-speaker and within-speaker variation in speech tempo of American English. J Acoust Soc Am 2010;128:839-50.
  9. Duchin SW, Mysak ED. Disfluency and rate characteristics of young adult, middle-aged, and older males. J Commun Disord 1987;20:245-57.
  10. Leeper L, Culatta R. Speech fluency: effect of age, gender and context. Folia Phoniatr Logop 1995;47:1-14.
  11. Shewan CM, Henderson VL. Analysis of spontaneous language in the older normal population. J Commun Disord 1988;21:139-54.
  12. Yairi E, Clifton NF. Disfluent speech behavior of preschool children, high school seniors, and geriatric persons. J Speech Lang Hear Res 1972;15:714-19.
  13. Jacewicz E, Fox RA, O’Neill C, Salmons J. Articulation rate across dialect, age, and gender. Lang Var Change 2009;21:233-56.
  14. Bóna J. Temporal characteristics of speech: the effect of age and speech style. J Acoust Soc Am 2014;136:116-21.
  15. Searl JP, Gabel RM, Fulks JS. Speech disfluency in centenarians. J Commun Disord 2002;35:383-92.
  16. Nabavi SH, Shoja M, Mohammadi S, Rashedi V. Health-related quality of life in community-dwelling older adults of Bojnourd. Journal of North Khorasan University of Medical Sciences 2014;6:433-9.
  17. Hunter EJ, Kapsner-Smith M, Pead P, Zito Engar M, Brown WR. Age and Speech Production: A Longitudinal Study of 50 Years. J Am Geriatr Soc 2012;60:1175-7.
  18. Jacobi I, Van der Molen L, Huiskens H, Van Rossum MA, Hilgers FJ. Voice and speech outcomes of chemoradiation for advanced head and neck cancer: a systematic review. Eur Arch Otorhinolaryngol 2010;267:1495-505.
  19. Yorkston KM, Bourgeois MS, Baylor CR. Communication and Aging. Phys Med Rehabil Clin N Am 2010;21:309-19.
  20. Ghasisin L. Examining the nature and electrophysiological features of lexical access processes in fluent and non- fluent aphasic patients. PHD thesis, University of Social Welfare and Rehabilitation, Tehran, 2014.
  21. Harel BT, Cannizzaro MS, Cohen H, Reilly N, Snyder PJ. Acoustic characteristics of Parkinsonian speech: a potential biomarker of early disease progression and treatment. J Neuroling 2004;17:439-53.
  22. Harnsberger JD, Shrivastav R, Brown WS, Rothman H, Hollien H. Speaking Rate and Fundamental Frequency as Speech Cues to Perceived Age. J Voice 2008;22:58-69.
  23. Benjamin BJ. Phonological performance in gerontological speech. J Psycholinguist Res 1982;11:159-67.
  24. Zellner B . Pauses and the temporal structure of speech; in Keller E (ed): Fundamentals of speech synthesis and speech recognition ;1994, p. 41-62. Chichester: John Wiley.
  25. Singh S, Bucks R, Cuerden J. Evaluation of an objective technique for analyzing temporal variables in DAT spontaneous speech. Aphasiology 2001;15:571-83.
  26. Allen GD. Speech rhythm: its relation to performance universals and articulatory timing. J Phon 1975;3:75-86.
  27. Van Brenk F. An articulographical analysis of age-related speaker variation Effects of speech rate on speech kinematics in younger and older adults (Master’s Thesis). The Study of the Language Faculty. Utrecht University, 2009.
  28. Goozee JV, Stephenson DK, Murdoch B E, Darnell RE, Lapointe LL. Lingual kinematic strategies used to increase speech rate. comparison between younger and older adults. Clin Linguist Phon 2005;19:319-34.
  29. Raming LA. Effects of physiological aging on speaking and reading rates. J Commun Disord 1983;16:211-26.
  30. Smith BL, Wasowicz J, Preston J . Temporal characteristics of the speech of normal elderly adults. J Speech Hear Res 1987;30:522-9.
  31. Van Brenk F, Terband H, van Lieshout P, Lowit A, Massen B. An analysis of speech rate strategies in aging. Interspeech 2009;6:792-5.
  32. Shumway-Cook A, Woollacott M. Attentional demands and postural control: the effect of sensory context. J Gerontol A Biol Sci Med Sci 2000;55(1):10-6.
  33. Brauer SG, Woollacott M, Shumway-Cook A. The influence of a concurrent cognitive task on the compensatory stepping response to a perturbation in balance-impaired and healthy elders. Gait Posture 2002;15(1):83-93.
  34. Hooper CR, Cralidis A. Normal Changes in the Speech of Older Adults: You’ve still got what it takes; it just takes a little longer! Perspectives on Gerontology 2009;14(2):47-56.

Fig.1

Changes in SLD, OD, speech rate, articulation rate, duration of pauses and frequency of pauses in decade life

References

  1. Don S, Lickley R. Uh I forgot what I was going to say: How memory affects fluency. The 7th Workshop on Disfluency in Spontaneous Speech; 2015 August.

  2. Thelen E, Smith LB. Dynamic systems theory; in Damon W, Lerner RM (ed): Handbook of child psychology: Theoretical models of human development;2006, p. 258-312.


  3. Torre III P, Barlow JA. Age-related changes in acoustic characteristics of adult speech. J Commun Disord 2009; 42:324-33.


  4. Kent RD. Research on speech motor control and its disorders: A review and prospective. J of Commun Disord 2000;33:391-428.


  5. Bortfeld H, Leon SD, Bloom JE, Schober MF, Brennan SE. Disfluency rates in conversation: Effects of age, relationship, topic, role, and gender. Lang speech 2001;44:123- 47.


  6. Andrade CRF, Martins VO. Speech fluency variation in elderly (original title: Variação da fluência da fala em idosos). Pro Fono 2010;22:13-18.


  7. Chon H, Sawyer J, Ambrose NG. Differences of articulation rate and utterance length in fluent and disfluent utterances of preschool children who stutter. J Commun Disord 2012;45:455-67.


  8. Jacewicz E, Fox RA. Between-speaker and within-speaker variation in speech tempo of American English. J Acoust Soc Am 2010;128:839-50.


  9. Duchin SW, Mysak ED. Disfluency and rate characteristics of young adult, middle-aged, and older males. J Commun Disord 1987;20:245-57.


  10. Leeper L, Culatta R. Speech fluency: effect of age, gender and context. Folia Phoniatr Logop 1995;47:1-14.


  11. Shewan CM, Henderson VL. Analysis of spontaneous language in the older normal population. J Commun Disord 1988;21:139-54.


  12. Yairi E, Clifton NF. Disfluent speech behavior of preschool children, high school seniors, and geriatric persons. J Speech Lang Hear Res 1972;15:714-19.


  13. Jacewicz E, Fox RA, O’Neill C, Salmons J. Articulation rate across dialect, age, and gender. Lang Var Change 2009;21:233-56.


  14. Bóna J. Temporal characteristics of speech: the effect of age and speech style. J Acoust Soc Am 2014;136:116-21.


  15. Searl JP, Gabel RM, Fulks JS. Speech disfluency in centenarians. J Commun Disord 2002;35:383-92.


  16. Nabavi SH, Shoja M, Mohammadi S, Rashedi V. Health-related quality of life in community-dwelling older adults of Bojnourd. Journal of North Khorasan University of Medical Sciences 2014;6:433-9.


  17. Hunter EJ, Kapsner-Smith M, Pead P, Zito Engar M, Brown WR. Age and Speech Production: A Longitudinal Study of 50 Years. J Am Geriatr Soc 2012;60:1175-7.


  18. Jacobi I, Van der Molen L, Huiskens H, Van Rossum MA, Hilgers FJ. Voice and speech outcomes of chemoradiation for advanced head and neck cancer: a systematic review. Eur Arch Otorhinolaryngol 2010;267:1495-505.


  19. Yorkston KM, Bourgeois MS, Baylor CR. Communication and Aging. Phys Med Rehabil Clin N Am 2010;21:309-19.


  20. Ghasisin L. Examining the nature and electrophysiological features of lexical access processes in fluent and non- fluent aphasic patients. PHD thesis, University of Social Welfare and Rehabilitation, Tehran, 2014.


  21. Harel BT, Cannizzaro MS, Cohen H, Reilly N, Snyder PJ. Acoustic characteristics of Parkinsonian speech: a potential biomarker of early disease progression and treatment. J Neuroling 2004;17:439-53.

  22. Harnsberger JD, Shrivastav R, Brown WS, Rothman H, Hollien H. Speaking Rate and Fundamental Frequency as Speech Cues to Perceived Age. J Voice 2008;22:58-69.


  23. Benjamin BJ. Phonological performance in gerontological speech. J Psycholinguist Res 1982;11:159-67.


  24. Zellner B . Pauses and the temporal structure of speech; in Keller E (ed): Fundamentals of speech synthesis and speech recognition;1994, p. 41-62. Chichester: John Wiley.


  25. Singh S, Bucks R, Cuerden J. Evaluation of an objective technique for analyzing temporal variables in DAT spontaneous speech. Aphasiology 2001;15:571-83.


  26. Allen GD. Speech rhythm: its relation to performance universals and articulatory timing. J Phon 1975;3:75-86.


  27. Van Brenk F. An articulographical analysis of age-related speaker variation Effects of speech rate on speech kinematics in younger and older adults (Master’s Thesis). The Study of the Language Faculty. Utrecht University, 2009.


  28. Goozee JV, Stephenson DK, Murdoch B E, Darnell RE, Lapointe LL. Lingual kinematic strategies used to increase speech rate. comparison between younger and older adults. Clin Linguist Phon 2005;19:319-34.


  29. Raming LA. Effects of physiological aging on speaking and reading rates. J Commun Disord 1983;16:211-26.


  30. Smith BL, Wasowicz J, Preston J . Temporal characteristics of the speech of normal elderly adults. J Speech Hear Res 1987;30:522-9.


  31. Van Brenk F, Terband H, van Lieshout P, Lowit A, Massen B. An analysis of speech rate strategies in aging. Interspeech 2009;6:792-5.


  32. Shumway-Cook A, Woollacott M. Attentional demands and postural control: the effect of sensory context. J Gerontol A Biol Sci Med Sci 2000;55(1):10-6.


  33. Brauer SG, Woollacott M, Shumway-Cook A. The influence of a concurrent cognitive task on the compensatory stepping response to a perturbation in balance-impaired and healthy elders. Gait Posture 2002;15(1):83-93.


  34. Hooper CR, Cralidis A. Normal Changes in the Speech of Older Adults: You’ve still got what it takes; it just takes a little longer! Perspectives on Gerontology 2009;14(2):47-56.