|Year : 2012 | Volume
| Issue : 1 | Page : 21-25
Voice characteristics of elderly college teachers: A pilot study
Prakash Boominathan1, Shenbagavalli Mahalingam1, John Samuel2, Mumudi V Dinesh Babu3, Aishwarya Nallamuthu1
1 Department of Speech, Language and Hearing Sciences, Sri Ramachandra University, Chennai, India
2 Department of ENT and HNS, Sri Ramachandra University, Chennai, India
3 Department of ENT (Audio Vestibular Section), Christian Medical College and Hospital, Vellore, Tamil Nadu, India
|Date of Web Publication||9-Apr-2012|
Department of Speech, Language and Hearing Sciences, Sri Ramachandra University, Porur, Chennai - 116
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Rise in the age of retirement for teachers has created opportunities to continue in the profession even after 60 years of age. Elderly teachers will be more prone to developing voice problems due to their continuing teaching assignments, and age-related changes in larynx. Aim: To profile the voice characteristics of elderly teachers through comprehensive voice assessment. Design: Cross-sectional study. Materials and Methods: Stroboscopic, perceptual, acoustic, aerodynamic, and self percept features of voice in 20 elderly teachers were assessed using the Sri Ramachandra voice assessment protocol. Statistical Analysis: Differences between genders were calculated using independent t-test. Inter-judge reliability for perceptual analysis was calculated using intra-class correlation coefficient. Results: Stroboscopy revealed sarcopenic changes of vocal muscles, such as discoloration of vocal folds, incomplete closure, and reduced mucosal waves. On GRBAS scale, the subjects were rated as predominantly breathy, asthenic, and strained. Subjects showed reduced Maximum Phonation Time (11-13 seconds) and increased s/z ratio (1.21 in males and 1.19 in females). Mean F0 was 121 Hz (males) and 172 Hz (females). Mean I 0 range [28.4 dB (A) in males and 24.2 dB (A) in females] was reduced and shimmer (5.80% in males and 4.84% in females) values were increased. Dysphonia Severity Index revealed mild to moderate deviation (0.07 in males and 0.16 in females). However, on self evaluation of voice through Voice Disorder Outcome Profile, scores revealed certain physical changes with less or no obvious functional limitation. Conclusion: This study documents the trends in voice-related changes in elderly teachers. This information may be crucial for voice professionals to advice elderly teachers and management to advocate "good vocal health."
Keywords: Dysphonia Severity Index, elderly teachers, voice analysis, voice protocol
|How to cite this article:|
Boominathan P, Mahalingam S, Samuel J, Dinesh Babu MV, Nallamuthu A. Voice characteristics of elderly college teachers: A pilot study. J Laryngol Voice 2012;2:21-5
| Introduction|| |
Regulatory bodies in India have recently enhanced the permissible upper age limit of college teachers. Currently, opportunities are available for teachers to remain in teaching even after retirement. Elderly professors are given an emirital status after their retirement and continue to teach till the age of 70 years and above. Teachers are more prone to voice problems due to excessive stress and prolonged use of voice for teaching.  Changes in pitch, hoarseness, pitch break, increased strain, voice breaks, vocal tremor, breathiness, instability, reduced loudness, vocal fatigue, physical fatigue, and inadequate breath support for speaking are characteristics of "senile" voice of the elderly.  It is difficult to surmise whether the voice problems in elderly teachers are due to the process of aging or teaching. Furthermore, a probe into health-related issues and life style factors may help identify risk factors that are relevant to the Indian environment. Thus, this pilot study was conceived to carry out a multiparametric voice analysis in elderly teaching staff to characterize their voice.
| Aim|| |
The present study aimed to profile the voice characteristics of 20 elderly college teachers using the Sri Ramachandra voice assessment protocol. 
| Materials and Methods|| |
Twenty elderly teachers from a university teaching hospital (11 males and 9 females) in the age range of 60 to 75 years (Mean: 64.3 years; SD: 3.6) participated in the study. The details regarding teaching experience and hours of teaching per week are tabulated in [Table 1].
The Sri Ramachandra voice assessment protocol  was used to profile the voice characteristics of elderly teachers. The protocol included the following:
Stroboscopic analysis: The Atmos Media stroboscope was used to obtain laryngeal images which were assessed by the Otolaryngologist and Speech Language Pathologist (SLP) for structure and function. The parameters  assessed were glottal closure, regularity, symmetry of the vocal fold vibration, mucosal wave and amplitude of vocal fold vibration, non vibratory portion (if any), and hyper-adduction of ventricular bands. The findings were tabulated and descriptive statistics was applied.
Perceptual analysis: The perceptual evaluation was done for both phonation and conversation samples and was judged by two SLPs independently. The GRBAS scale  was used for the perceptual analysis of voice for conversation tasks and phonation samples were judged for pitch, loudness, and quality. Inter-judge reliability was calculated using intra-class correlation coefficient.
Aerodynamic and Acoustic analysis: The subjects were instructed to phonate /a/, /i/, and /u/ for three trials and the maximum was taken as Maximum Phonation Time (MPT). s/z ratio was also calculated. LingWaves Phonetogram Pro and Signal Analysis - phonetogram module (version 2.4) was used to measure Dysphonia Severity Index (DSI). Following steps were used to obtain a phonetogram: The subjects were modeled by the clinician to sustain the vowel /a/ at four levels: Low pitch-low intensity; low pitch-high intensity; high pitch-low intensity; and high pitch-high intensity and the samples were recorded.
Frequency-, intensity-, and perturbation-related parameters were extracted and DSI  was calculated using the formula:
DSI = 0.13 x MPT + 0.0053 x F 0 -high - 0.26 x I 0 -low - 1.18 x jitter + 12.4
The data obtained from aerodynamic and acoustic analysis were descriptively analyzed using mean and standard deviation. Significant difference between males and females were calculated using independent t-test.
Self evaluation of voice: Voice Disorder Outcome Profile (V-DOP)  was used to collect information on self-perceived severity of the voice problem. It consisted of two parts. The first part included a question regarding the severity of the voice problem and the second part included 32 questions under three domains: physical, emotional, and functional. The severity ranged from normal to severe in a visual analogue scale. Furthermore, information on vocal health and related concerns/perceptions of communication in daily life from elderly teachers was also collected using 10 open-ended questions. In addition to the 10 questions, two questions were included for female subjects (Appendix 1). Descriptive statistics was applied.
| Results|| |
Structural and functional changes in larynx were observed in all subjects who consented for stroboscopic evaluation. Among males, 50% of them had grade II sulcus vocalis, 25% had atrophic changes, and 25% had interarytenoid edema with features of laryngopharyngeal reflux disease. Among females, 33.3% of them had interarytenoid edema, 16.4% had laryngopharyngeal reflux signs, and 50% of them had hypofunctional voice with mild compensation with ventricular folds. The findings of various parameters on stroboscopic evaluation are tabulated in [Table 2]. The results revealed that 50% of males and 83.3% of females had incomplete closure. Different patterns of incomplete closure was observed, among which 33% of the females had longitudinal gap, 25% of males, and 16.7% of females had irregular closure, 16.7% of the females had anterior gap, 25% of the males had vocal fold bowing, and 16.7% of females had double gap.
|Table 2: Stroboscopic findings across gender (n:10, Males: 4; Females: 6)|
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Perceptual analysis of voice
Phonation samples were judged for the perceptual correlates of voice. Intra-class correlation coefficient was used to find out the inter-rater reliability for the samples that was rated by judges 1 and 2. The results obtained indicated good inter-rater reliability (r>0.6). Overall perceptual qualities of voice revealed mild to severe deviance in grade, breathiness, asthenia, and strain. Roughness was perceived to have mild to moderate deviance. Deviation in the pitch was found in 65% of males and 67% of females. 45% of the subjects had soft voice and the rest spoke loud. Along with the soft voice, tremors and nasality were also noticed. Deviant voice quality was observed in all the subjects. Pitch breaks were noticed in 73% of males and 56% of females and voice breaks were noticed in 73% of males and 44% of females.
Simple aerodynamic measurements
[Table 3] presents the mean, standard deviation, and P values across gender for MPT and s/z ratio. In the present study, MPT for /a/ (males: 13.27 seconds and females: 12.67 seconds), /i/ (males: 12.45 seconds and females: 11.44 seconds), and /u/ (males: 11.55 seconds and females: 10.78 seconds) was found to be reduced in both genders than the expected adult norms and there was no significant difference between male and female subjects. A normal adult can sustain a vowel for more than 15 seconds according to Indian norms.  The s/z ratio was 1.21 in males and 1.19 in females which was found to be increased. However, no significant difference between men and women were noticed. The normal s/z ratio ranges between 0.9 second to 1.1 second.  Comparisons are made with adult norms as there are no established geriatric norms for Indian population. Developing geriatric norms may be essential considering the current increase in this population set.
|Table 3: Mean, Standard deviation (SD), and P values across gender for Maximum Phonation Time (/a/, /i/, and /u/) and s/z ratio (n: 20)|
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The average fundamental frequency (F0) for phonation in males was 121.3 Hz (SD: 46.4) and 172.1 Hz (SD: 32.6) in females. Lowest F0 in males was found to be 99.4 Hz (SD: 15.4) and 143.7 Hz (SD: 21.6) in females. Highest F0 was found to be 204.7 Hz (SD: 59.6) in males and 281.6 Hz (SD: 69.8) in females. The mean speaking fundamental frequency (SF0) was 132.3 Hz (SD: 31.9) in males and 173.3 Hz (SD: 32.5) in females.
The average I0 was found to be 66.2 dB(A) (SD: 6.0) in males and 62.8 dB(A) (SD: 2.2) in females. Lowest I0 was found to be 60.5 dB(A) (SD:6.6) in males and 57.9 dB(A) (SD: 2.9) in females. Highest I0 was found to be 83.4 dB(A) (SD:13.5) in males and 82.0 dB(A) (SD:4.2) in females. The I0 range was 28.4 dB(A) (SD: 5.9) in males and 24.2 dB(A) (SD:6.5) in females which was found to be reduced. The minimum Io and maximum Io in normal is around 50 dB and 115 dB, respectively.  However, the elderly population had reduced lowest and highest limits of the intensity.
Perturbation- and Quality-related measures
In the present study, the average jitter values were 0.30% (SD: 0.3) in males and 0.26% (SD: 0.3) in females. The shimmer values in males (5.80%, SD: 1.9) and females (4.84%, SD: 1.4) were increased when compared with the normative value.  This increased shimmer levels in the present study could be attributed to the aperiodicity and irregular closure pattern of the vocal folds. The DSI revealed mild to moderate deviation (0.07, SD: 1.1) in males and (0.16, SD: 1.2) in females when compared with the normative range  in both genders.
Self perceptual evaluation (V-DOP)
Self evaluation of voice plays an important role in the voice assessment. The mean and standard deviation of each domain in V-DOP and total V-DOP score are tabulated in [Table 4].
|Table 4: Mean and standard deviation of each domain in V-DOP and total V-DOP score (n:20)|
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The results of self perceptual evaluation revealed that the overall severity was zero which indicated that the subjects who participated in the study did not experience/feel any voice problem. The scores revealed concerns predominantly related to physical aspects of voice. The results are presented in [Table 5].
|Table 5: Perception of voice for daily communication by the subjects (n:20)|
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Overall, 22.2% of subjects reported to perceive changes in voice and 11.1% have undergone voice training or vocal surgery. It is also found that female subjects reported to have more problem than male subjects. On analyzing the social habits of elderly teachers, 27.3% of males reported to be involved in active or passive smoking and 36.4% of males consumed alcohol.
| Discussion|| |
Elderly teachers have high demands on their vocal mechanism. So, it is important to carry out an evaluation on the elderly teaching staff to profile their voice characteristics using a comprehensive voice assessment. The results of stroboscopic analysis in this study supports the findings obtained by Linville,  stating that elderly speakers displayed a high incidence of glottic gaps in phonation condition. On analyzing the other parameters of stroboscopic analysis, the results supported the findings of a study done in 1980,  stating that elderly population are found to have greater aperiodicity of vocal fold vibration, incomplete glottal closure, mucosal wave alterations, and reduced amplitude of vibration when compared with their younger population. The vocal hyper-adduction noted in these subjects may be attributed to the compensatory movement due to structural changes or can be a behavioral manifestation (hyperfunction) as a result of teaching.
Pitch breaks, devoicing, tremulous, and weak voices are the other characteristics of voice that were seen in elderly population. Perceptually, an increase in pitch is noticed with aging men and decrease in pitch is noticed with aging women. Geriatric voices have reduced loudness, breathiness, relatively higher pitch, diminished flexibility, and tremulousness.  Elderly women had mild to moderate deviation on the overall parameters of dysphonia, roughness, breathiness, and instability of the GRBAS scale.  In the present study, the deviations in the quality were probably due to the atrophic changes, glottal incompetence, asymmetry, and aperiodicity of the vocal folds. Perceived changes in parameters of voice could be due to tremor and instability consequent to age-related structural changes in the larynx.
On analyzing the aerodynamic measures, the reduction in MPT may be due to decreased breath support and improper glottal closure during vocal fold vibration. Increased s/z ratio could be due to the changes that takes places in respiratory  and laryngeal systems  due to aging. The results obtained from the acoustic analysis are in accordance with Morsomme et al. who stated that the mean speaking fundamental frequency (SF0) alters with aging. The findings of the present study do not differ from the expected changes in F0- and I0-related measures reported in the literature. The reduced I0 range can be due to the inadequate closure of the vocal folds and decreased flexibility in use of loudness in speaking. The results support the finding of Morsomme et al.  who stated that elderly population had increased jitter and shimmer levels. The deviance noticed in DSI is conceivable as the parameter like highest F0 is reduced, lowest I0 is increased, and MPT is reduced.
However, these changes did not affect the functional aspects of voice. Despite deviations found in laboratory measures of voice, the subjects in this study did not perceive any change or deviations in their voice for functional and practical purposes. It is very important to know the individual's perception on their voice which can give an overall impression and how concerned are they on their voice. A questionnaire probing the perceptions of voice for communication in daily life was attempted. Most of the elderly teachers who reported to have changes in voice did not report a negative impact of voice change on day-to-day communication.
| Conclusion|| |
In this study, the results revealed deviations in simple aerodynamic measures, perceptual evaluation by SLP, acoustic analysis of voice, and stroboscopic findings. However, the self assessment of voice by the subjects showed no "perceived" voice problems. These findings reveal that the elderly teachers did not "feel" the process of aging in voice or the impact of teaching, even though there were significant deviances in voice identified through laboratory-based measurements.
Laboratory findings ascertained age-related expected changes in vocal structure and physiology in this group of elderly teachers. These deviances (limitations) did not seem to interfere with their routine teaching jobs even after the age of 60 years. The reason could be attributed to the "insensitiveness" of the subjects to the changes in voice and inadequate knowledge about disordered voice. This insensitiveness could be because their voice changes could have been so gradual that the change is habituated than perceived as a difference. However, the deviations in voice cannot be predicted if it was due to aging or due to teaching. The information obtained from this pilot study delineates a trend in the voice findings from this group of elderly teachers. These may be crucial for voice professionals to advice teachers and management to advocate "good vocal health." Furthermore, a study is planned with increased sample size to look into the reasons for the voice problems in elderly teachers.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]