The Effects of Size and Type of Vocal Fold Polyp on Some Acoustic Voice Parameters.

BACKGROUND: Vocal abuse and misuse would result in vocal fold polyp. Certain features define the extent of vocal folds polyp effects on voice acoustic parameters. The present study aimed to define the effects of polyp size on acoustic voice parameters, and compare these parameters in hemorrhagic and non-hemorrhagic polyps. METHODS: In the present retrospective study, 28 individuals with hemorrhagic or non-hemorrhagic polyps of the true vocal folds were recruited to investigate acoustic voice parameters of vowel/ æ/ computed by the Praat software. The data were analyzed using the SPSS software, version 17.0. According to the type and size of polyps, mean acoustic differences and correlations were analyzed by the statistical t test and Pearson correlation test, respectively; with significance level below 0.05. RESULTS: The results indicated that jitter and the harmonics-to-noise ratio had a significant positive and negative correlation with the polyp size (P=0.01), respectively. In addition, both mentioned parameters were significantly different between the two types of the investigated polyps. CONCLUSION: Both the type and size of polyps have effects on acoustic voice characteristics. In the present study, a novel method to measure polyp size was introduced. Further confirmation of this method as a tool to compare polyp sizes requires additional investigations.

Effects of transcutaneous electrical stimulation on vocal folds adduction.

According to most previous studies, inducing movements in internal laryngeal muscles by transcutaneous electrical stimulation (TES) was impossible. However, the movements have been reported after using needle electrodes inserted into the internal superior laryngeal nerve (ISLN). Herein, we aimed to apply an innovative TES protocol to cause movements in vocal folds. A short duration and high frequency electrical current was applied by two surface electrodes just above the entrance of ISLN to larynx. The subjects were 32 normal participants (mean age = 23.87; SD = 3.43). During TES application, the vocal folds' movements were examined by flexible videonasolaryngoscopy. Statistical paired t test was used to analyze the differences of vocal folds opening angle, in degrees, during rest and TES periods. Furthermore, the movements were judged by seven experienced speech pathologists via a 9-point rate scale from -1 (any abduction) to 8 (complete adduction). The mean vocal folds adduction increased by 35.68° (t = 9.35, p > 0.001) due to TES application. The mean qualitative scores assigned by raters to each subject were between 6 and 7 points, which indicate an acceptable adduction in vocal folds through TES. Unlike previous studies, the applied TES protocol in this research induced significant vocal fold movements. This might be attributed to our different stimulation parameters, which were designed to penetrate deeply and stimulate ISLN specifically. It is worth noting that we introduced a novel TES protocol, which should be confirmed and then examined as a complementary therapy for neurologic voice disorders in future studies.

Role of the Internal Superior Laryngeal Nerve in the Motor Responses of Vocal Cords and the Related Voice Acoustic Changes.

BACKGROUND: Repeated efforts by researchers to impose voice changes by laryngeal surface electrical stimulation (SES) have come to no avail. This present pre-experimental study employed a novel method for SES application so as to evoke the motor potential of the internal superior laryngeal nerve (ISLN) and create voice changes. METHODS: Thirty-two normal individuals (22 females and 10 males) participated in this study. The subjects were selected from the students of Iran University of Medical Sciences in 2014. Two monopolar active electrodes were placed on the thyrohyoid space at the location of the ISLN entrance to the larynx and 1 dispersive electrode was positioned on the back of the neck. A current with special programmed parameters was applied to stimulate the ISLN via the active electrodes and simultaneously the resultant acoustic changes were evaluated. All the means of the acoustic parameters during SES and rest periods were compared using the paired t-test. RESULTS: The findings indicated significant changes (P=0.00) in most of the acoustic parameters during SES presentation compared to them at rest. The mean of fundamental frequency standard deviation (SD F0) at rest was 1.54 (SD=0.55) versus 4.15 (SD=3.00) for the SES period. The other investigated parameters comprised fundamental frequency (F0), minimum F0, jitter, shimmer, harmonic-to-noise ratio (HNR), mean intensity, and minimum intensity. CONCLUSION: These findings demonstrated significant changes in most of the important acoustic features, suggesting that the stimulation of the ISLN via SES could induce motor changes in the vocal folds. The clinical applicability of the method utilized in the current study in patients with vocal fold paralysis requires further research.

Prevalence of Voice Disorders and Associated Risk Factors in Teachers and Nonteachers in Iran.

OBJECTIVES: Teachers are at increased risk for development of voice disorders. Because there is no published study on Iranian teachers, the aim of this study was to compare the prevalence of voice disorders among teachers and nonteachers in Iran and define the causing risk factors. METHODS: In the present study, 104 teachers and 41 nonteacher participants, whose jobs did not involve vocal effort, completed a questionnaire regarding to vocal complaint and four relevant risk factors. RESULTS: According to our gained data, 54.6% of teachers experienced vocal complaints during their work, although this value was 21.1% for the nonteacher group (P < 0.001). Moreover, investigating the prevalence of voice disorders during other periods of life was performed. Analyzing the questionnaire data indicated a significant higher vocal load risk factor for teachers (70.77%; standard deviation [SD], 29.48), in comparison with their nonteacher counterparts (27.44%; SD, 37.83; P < 0.001). In addition, our study revealed the significance of vocal load, as well as physical and environmental risk factors in the development of voice disorders in teachers with voice complaints. CONCLUSIONS: Present findings indicated a higher epidemiology of voice problems among teachers in comparison with nonteacher individuals and introduced vocal load as the most important risk factor in development of voice disorder in Iranian teachers. Accordingly, it is recommended to pay special attention to negative effects of vocal load, although environmental and physical factors are also of importance.

Translated Versions of Voice Handicap Index (VHI)-30 across Languages: A Systematic Review.

BACKGROUND: In this systematic review, the aim is to investigate different VHI-30 versions between languages regarding their validity, reliability and their translation process. METHODS: Articles were extracted systematically from some of the prime databases including Cochrane, googlescholar, MEDLINE (via PubMed gate), Sciencedirect, Web of science, and their reference lists by Voice Handicap Index keyword with only title limitation and time of publication (from 1997 to 2014). However the other limitations (e.g. excluding non-English, other versions of VHI ones, and so on) applied manually after studying the papers. In order to appraise the methodology of the papers, three authors did it by 12-item diagnostic test checklist in "Critical Appraisal Skills Programme" or (CASP) site. After applying all of the screenings, the papers that had the study eligibility criteria such as; translation, validity, and reliability processes, included in this review. RESULTS: The remained non-repeated articles were 12 from different languages. All of them reported validity, reliability and translation method, which presented in details in this review. CONCLUSION: Mainly the preferred method for translation in the gathered papers was "Brislin's classic back-translation model (1970), although the procedure was not performed completely but it was more prominent than other translation procedures. High test-retest reliability, internal consistency and moderate construct validity between different languages in regards to all 3 VHI-30 domains confirm the applicability of translated VHI-30 version across languages.

Objective vocal parameters in Farsi-speaking adults with Down syndrome.

Previous studies have indicated significant differences in vocal parameters between children with Down syndrome and normal children. This study was performed to see whether there is a significant dissociation between normal adults and adults with Down syndrome in terms of some vocal parameters. The participants were 22 adults with Down syndrome and 22 normal adults matched for age and gender. We measured jitter, shimmer, fundamental frequency (F0), and maximum phonation time (MPT). The results showed a significantly higher F0 and a significantly lower jitter in the Down syndrome group compared to the control group, while the average amounts of MPT and shimmer were not different. Moreover, the shimmer and jitter of females in both groups were lower than those of males. These findings might be the result of a physiological retardation of the larynx rather than mental retardation in the Down syndrome population.

Investigation of the reliability of the SSI-3 for preschool Persian-speaking children who stutter.

UNLABELLED: There is a pressing need in Iran for the translation of widely used speech-language assessment tools into Persian. This study reports the interjudge and intrajudge reliability of a Persian translation of the Stuttering Severity Instrument-3 (SSI-3) (Riley, 1994). There was greater than 80% interjudge and intrajudge agreement on scale scores for Frequency and Duration, 54% interjudge and 62.2% intrajudge agreement for "Physical Concomitants" and greater than 80% interjudge and intrajudge agreement for the Overall score. In conclusion, although percentage agreement for Physical Concomitant Behaviors was low, the Persian translation of SSI-3 shows otherwise acceptable interjudge and intrajudge reliability when performed under ideal conditions. EDUCATIONAL OBJECTIVES: The reader of this article will be able to: (1) explain the process of test translation from the original language to another language; (2) summarize the process of determining interjudge and intrajudge reliability of the SSI-3 in preschoolers.

Motor control of speaking rate and oral diadochokinesis in hearing-impaired Farsi speakers.

Although speech motor control has been studied intensively in normal-hearing and hearing-impaired (HI) speakers in America and Europe, essentially no research has been performed using Persian-speaking participants. A total of 46 prelingual hearing-impaired 15-18-year-old males and 15 normally hearing control participants from Iran participated in the study. Three speaking performance measures, oral diadochokinesis (DDK), speaking rate (words per minute), and intelligibility ratings, were obtained for the two groups and compared to previously published research for English-speaking participants. The DDK results in general showed that the normal-hearing group produced the fastest syllable rates, and the profoundly HI group produced the slowest. Similar results were obtained for speaking rates. Speech intelligibility was highest in the normal-hearing group and lowest in the profoundly HI group. Correlation analysis between DDK and speaking rates showed that for HI group only, a slow speaking rate corresponded to slow DDK rates. It is shown that generally there are significant differences in measures of speech motor control in normal-hearing and hearing-impaired participants. These results concord with those from other language groups.