Prevalence Of Voice Disorders In India

Published Date: 02 Nov 2017

Review of Literature

Voice disorders are differentially distributed based on the vocal demands of the individual. The individuals who work in various professions that require intense vocal loading like teachers, singers, newsreaders, call center customer service advisors and other fields that include students, home-makers, street-sellers, laborers etc. frequently report voice related symptoms.

Prevalence of Voice disorders in India

In India, a large number of individuals depend on their voice for their daily living (konnai et al., 2008). A survey on awareness of vocal hygiene was carried out in professional voice users by Boominathan et al., 2008 in India and the results revealed that the politicians and vendors had the highest point prevalence of voice problems, this is majorly caused due to the lack of awareness in regards to the availability of treatment of voice problems among these populations.

Boominathan, Chandrashekar, Nagarajan, Madraswala & Rajan (2008) reported that various factors such as lack of use of acoustic amplification in classrooms and during large meetings, noise, dust pollutions, dietary preferences (spicy foods, excessive caffeine consumptions) are the main cause of individuals susceptibility to voice problems among the Indian population. Despite the fact that the individuals are highly prone to voice problems, they do not seek professional help due to various factors such as lack of awareness of the availability of voice therapy, financial issues, expectation of improvement of their condition using home based remedies.

A survey done by Karki & Rai (2011) found that the most common voice disorder among the general population was habitual dysphonia followed by true vocal cord nodule. Potential environmental risk factors have been identified for a number of these vocally demanding professions e.g., extensive voice use without enough time for voice rest, to speak in high background noise, poor room acoustics, poor indoor air quality, poor speaking postures, and lack of appropriate technical aid such as voice amplifiers (Vilkman, 2004).

Approximately one third of the population are working in professions in which voice use is an essential, if not crucial, part of their work (Vilkman, 2004). Professional voice users can be classified as instructors/teachers (school teachers, pre-school teachers, fitness instructors), performers (broadcasters, actors, singers), persuasive voice users (politicians, lawyers, ministers, auctioneers, salespeople including telemarketers), service voice users (counselors, operators, customer service assistants) and professions within emergency (police, fire department, emergency medical technicians, air traffic controllers). The etiology and type of voice disorders varies with the type of occupation, age, gender, geographical locations.

Age and Gender Variations:

S.No

Author

Year

Age and Gender Variations

1

Roy, Merril, Thibeault, Parsa, Gray & Smith

2004

2,531randomly selected participants (1,243 teachers and 1,288 nonteachers) were studied.

The results revealed -

Women (46.3%), compared with men (36.9%), had a higher lifetime prevalence of voice disorders, and higher prevalence of chronic voice disorders (>4 weeks in duration)

2

Preciado, Pérez, Calzada & Preciado

2005

332 women (63%) and 189 men (37%) were studied.

The results revealed –

Organic lesions were more prevalent in women (25.4%) than in men (9.5%).

functional lesions and chronic laryngitis were more prevalent in men (36.5% and 13.2%) than in women (24% and 5%)

3

Roy, Stemple & Merill

2007

117 seniors (39 males and 78 females; mean age, 76.1 yr; SD, 8.5 yr; range, 65–94 yr) were studied

voice disorders are common among the elderly, with 29% of respondents reporting a current voice disorder

our prevalence estimates for the elderly population clearly point to substantially higher rates for both lifetime (47% of the patients) and current voice disorders (29% of the patients)

4

Angelillo, Maio, Costa, Angelillo & Barillari

2009

504 teachers (322 F – 182 M) with an age ranging between 24 and 62 years were studied.

The results revealed that

women as compared with men had a higher lifetime prevalence of voice disorders.

Occupation Based Voice Disorders

S.No

Author

Year

Occupation Based

1

William

2003

studied various occupations which are at risk for developing a voice disorders, he had found that among various occupations 13% salespersons, 14.5% factory workers, 10.6% clerical workers, 4.2% teachers, 0.19% counselors, 0.02% singers had voice problems ranging from mild to severe

2

Simberg

2004

719 teachers from a university were studied.

Results reveal one fifth of the teacher students reported frequently occurring vocal symptoms and that most of these students had an organic voice disorder.

Teacher reported more vocal symptoms occurring weekly or more frequently.

The proportion of teachers reporting vocal symptoms in comprehensive schools and upper secondary schools seems to have increased over a twelve-year period.

Furthermore, the proportion of teachers reporting two or more frequently occurring vocal symptoms also increased, suggesting that voice problems among teachers are increasing.

3

Roy, Merill, Gray & Smith

2004

The study included 2,401 participants from various schools (1,243 teachers and 1,279 non-teachers) of different age ranges.

The results revealed that teachers were significantly more likely than non-teachers to have experienced multiple voice symptoms and signs including hoarseness, discomfort, and increased effort while using their voice, tiring or experiencing a change in voice quality after short use, difficulty projecting their voice, trouble speaking or singing softly, and a loss of their singing range

4

Preciado, Pérez, Calzada & Preciado

2005

The study included 931 teachers from a high school.

The results revealed that the prevalence of voice disorders among teachers was 57%. 20.3% from organic lesions and 29% from functional disorders.

5

Boominathan, Rajendran, Nagarajan, Seethapathy, Gnanasekar

2008

400 subjects in the age range of 25 to 45 which includes100 singers (54 males and 46 females), 100 politicians (100 males), 100 teachers (24 males and 76 females) and 100 vendors (72 males and 28 females) who were hawkers were studied.

The results revealed –

86% politicians, 74% vendors highest prevalence of voice problem, 59% singers and 49% teachers were reported to have voice problems with varying degrees of severity.

6

Mendes, Salema, Rodrigues, Bonança & Santos

2009

73 teachers that use their voice as professional tool (teachers’ group) and 73 non-voice professionals.

Results revealed that the teachers’ group presented a higher prevalence of vocal problems than the control group: 52% reported hoarseness, 46.6% vocal fatigue and 45.2% vocal discomfort compared with 31.5%, 20.5 % e 28.7%, respectively.

7

Bahar, Tanja, Irena & Boltežar

2011

300 randomly chosen physicians working as general practitioners were studied.

The results revealed that

82.8 % of the physicians reported having voice problems during their entire career, with 7.6 % of them experiencing frequent voice problems.

8

Higgins & Smith

2012

100 faculty from a university were selected for the study.

The results of the study revealed

45 reported vocal difficulties that were substantial enough to interfere with normal communication. Symptoms were consistent with vocal overuse, including increased effort, hoarseness, decreased loudness, and vocal discomfort.

Demographic and health/behavioral risk factors (e.g., age, gender, allergies, acid reflux, use of tobacco/alcohol) had little apparent effect on the prevalence of a voice disorder

Voice disorders are multidimensional phenomena that are usually understood to include a self-perceived reduction in physical, social, emotional, or professional well-being due to voice problem. Studies across several continents reveal that females as compared with males had a higher prevalence of voice disorders regardless of occupational status and age. Furthermore, female not only reported higher rates of voice disorders, but they also reported more chronic voice disorders (i.e., voice problems greater than 4 weeks in duration), regardless of age. Various findings reveal that women seem to be more likely to report and seek help for voice-related problems has been well documented in various studies (Coyle, Weinrich, & Stemple, 2001; Lejska, 1967; Marks, 1985; Pekkarinen, Himberg, & Pentti, 1992; Smith et al., 1998).

Studies across several continents consistently point to teaching as a particular occupational risk for experiencing a voice problem; some studies indicate that nearly 50% of teachers experience voice problems at any given point in time. A large proportion of teachers with voice problems miss work because of their voice problem.

Female teachers are at greater risk for perceiving a voice problem than males, and physical education teachers appear to be at greater risk than other categories of teachers. Other professions such as singers experiencing a voice problem at any given moment in time ranging from about 20 to 50%, similar factors may influence the likelihood of a voice problem for both singers and non-singer. Occupations requiring significant vocal loading, such as lawyer, clergy, cheer leaders, factory workers, clerical workers, counselors, call center employees may have an increased risk for seeking treatment due to a voice problem.

Clinical Analysis of Vocal Symptoms:

The voice as sound source for eliciting speech is a pre-condition for verbal human communication. Hence, the presence of voice disorder can disrupt the ability to communicate and therefore cause an impact to the psychological and social well-being of the person (Rasch, Günther, Hoppe, Eysholdt & Rosanowski, 2005).

Due to the impact of voice disorder on communication and quality of the patients’ life, there is a need for clinical analysis to provide appropriate interventions in order to restore patients’ health and therefore the quality of life.The European Laryngological Society (ELS) recommends five key components of clinical voice evaluation: the perceptual analysis, the self-evaluation of the patient, the acoustic analysis, the visual inspection of vocal fold vibration and the aerodynamic assessment (Dejonckere et al, 2001).

The major purposes of clinical assessment of the voice disorders are

To help in assessment of voice patients.

To determine the degree and the extent of the cause of disease

To evaluate the degree and the nature of disorder

To determine the prognosis and monitor changes in the treatment. (Hirano, 1981)

voice assessment techniques can be divided as follows

The acoustic analysis also known as the gold standard, is based on objective parameter analysis and provides discrimination between healthy and pathological voices. Objective perturbation measures as fundamental frequency, jitter and shimmer or multi-parametric analysis like the Dysphonia Severity Index (DSI) are widely used in clinical diagnosis. All acoustic analyses require a controlled environmental condition for reliable measurements. Acoustic analysis of the voice signal is the most useful method for assessing pathological phonatory function because it is non-invasive and provide objective data. Such quantitative measurement of voice quality is useful for monitoring changes during the course treatment of disorders.

Acoustical analysis and air flow studies are an instrumental measure of voice and a useful for vocal analysis. Much effort has been expended in acoustic and speech study toward the search for standardized acoustic parameters that are reliable and reproducible among different subjects and have diagnostic value for various vocal pathologies.

The frequency is the rate of vibration of the vocal folds measured in cycles per second or Hertz. The fundamental frequency is the most comfortable pitch delivered by the larynx in a given individual. The pitch of the voice and fundamental frequency are inversely related. Pitch can be measured by wave form analysis of the voice. The mean fundamental frequency is an average value that is calculated during sustained vowels or extracted during speech. The phonation range is the range of fundamental frequencies an individual can produce.

Intensity is a measure of loudness. On an acoustic waveform, intensity corresponds to the amplitude height. Maximal and minimal intensity can be measured at different fundamental frequencies to graph a phonetogram. Jitter and shimmer are two perturbation measures.

Perturbation is the cycle to cycle variability of the acoustic waveform during a sustained vowel. Shimmer is the perturbation in intensity or loudness, and jitter is the perturbation in frequency. These measures correspond to how smooth a voice sounds. These values are most consistent in the absence of significant dysphonia/dysarthria as it takes a sustained uninterrupted vowel sound to measure wave forms.

Perturbation parameters are not useful for patients with severe dysphonia and dysarthria; however, they can be used to evaluate clinical treatment efficacy. Signal to noise ratios are measures comparing harmonic signal energy to aperiodic or noise energy. During smooth, uninterrupted vocalization, the majority of energy is harmonic and forms well-defined, periodic waveforms. As the mucosal wave is disrupted, the acoustic waveforms become irregular, forming white noise. Generally, large noise energy with greater random aperiodicity represents abnormal vocal function.

Acoustic analysis testing in general requires a rigorously standardized testing environment, skilled evaluators, and highly motivated voice users.

Accurate wave forms are difficult to elicit in the presence of severe dysphonia or dysarthria, rendering most parameters inconsistent. While clinical correlation to mucosal wave vibration, glottic closure and power is possible, acoustic parameters do not have diagnostic value for the localization of vocal pathology.

The perceptual analysis like GRBAS (Grade, Roughness, Breathiness, Asthenia, and Strain), RBH (Roughness, Breathiness, and degree of Hoarseness), CAPEV (Consensus Auditory Perceptual Ratings of Voice), AVQI (Acoustic Voice Quality Index) are utilized by the clinician to ascertain voice quality.

The evaluation of vocal fold vibration during phonation by videostroboscopy is a common clinical voice assessment tool. The characteristics of vocal fold vibration can be evaluated by this laryngeal imaging technique in terms of regularity and periodicity of vibration, symmetry of motion, mucosal wave, glottal closure and a lot more parameters. The videostroboscopy technique relies on the quasi-periodic nature of vocal fold vibration and the determination of the fundamental frequency (f0). Reliability of videostroboscopy in assessing vocal fold vibratory characteristics is affected when the voice is severely disturbed and therefore the tracking of f0 is not possible. Videostroboscopy enables the subjective determination of vibratory patterns. Parameters are regularity and periodicity of vibrations, symmetry of motion between the vocal folds, phase symmetry, vibratory amplitude, glottal closure, vertical level, mucosal wave, and tissue pliability.

The aerodynamic assessment of phonation is an objective measurement which is dependent on the fundamental frequency, type of speech task and intra-subject variability. There is no normative set for application in research and clinical practice. Aerodynamic measures commonly used in the clinic include: glottal airflow rates, glottal pressure, and airway resistance.

Clinical Method

Signal

Parameter

Evaluation

Acoustic analysis

Perturbation measures

Acoustic

Jitter, shimmer, fundamental frequency (Fo), Fo dynamic range, intensity (Io), Io dynamic range, DSI

Objective

Perceptual analysis

GRBAS, CAPE-V

Acoustic

Grade, Roughness, Breathiness, Asthenia, Strain

Subjective

Vocal Fold vibration

Video stroboscopy

Dynamic

Mucosal wave

Objective + subjective

Aerodynamic Analysis

Phonatory aerodynamic system

Flow

MPT, S/Z ratio

Objective + subjective

Voice problems are multifactorial in origin. Although a detailed history may point to the diagnosis, in many cases it is impossible to exclude malignancy and other physical abnormalities without a detailed clinical assessment. In primary care, the risk of malignancy needs to be carefully assessed and an urgent referral made if it is a possibility. In other cases, with an obvious primary cause, simple lifestyle, vocal hygiene and dietary advice or a therapeutic medical trial is worth considering. All other cases need referral for laryngeal examination.

In summary it is highly essential to know the epidemiology of voice disorders and the type of occupation, location, age, gender and how the effect of voice disorder has impacted their work life. It is also essential to identify the vocal and vocal habits, acoustic and aerodynamic characteristics and stroboscopy findings of individuals with voice disorders.

The current study focuses on the investigating the percentage of voice disorders among general populations. The study also focuses on determining the stroboscopy findings, acoustic and aerodynamic characteristics, vocal and non-vocal habits in different age groups and voice disorders.