Radish Kumar Balasubramanium

Cepstral Analysis of Voice in Unilateral Adductor Vocal Fold Palsy

OBJECTIVES Unilateral vocal fold paralysis (UVFP) occurs because of the dysfunction of the vagus nerve innervating the larynx. It causes a characteristic breathy voice often accompanied by swallowing disability, a weak cough, and the sensation of shortness of breath. Clinical evaluation of voice is generally based on perceptive criteria and the acoustic analysis of voice. In the present study, it is hypothesized that there would be an abnormal reduction of the cepstral peak in speakers with UVFP relative to the normal controls, as they are characterized by a breathy voice because of inadequate closure of vocal folds. METHODS Phonation of sustained vowel /a/ sample was subjected to acoustic analysis using Computerized Speech Lab (CSL model 4150; Kay Pentax, Lincoln Park, NJ) software. The vowels were analyzed acoustically by the measurement of cepstral peak prominence (CPP). RESULTS The results of 2 × 2 analysis of variance revealed the main effects of the groups (clinical vs control group), indicating reduced cepstral peak value in the clinical group in comparison with controls. The main effect of gender was also significant, indicating a decrease in the CPP value in the female group in comparison with the male group. The results obtained were discussed with respect to the underlying pathophysiology. CONCLUSION The present study investigated the CPP in subjects with UVFP. Cepstral deviations in the clinical group are explained to be the result of the presence of phonatory gap, leading to the lower values of CPP.

Cepstral Analysis of Sexually Appealing Voice

OBJECTIVES OF THE STUDY In spite of voice being an important parameter of mate choice, none of the studies have described the acoustic characteristics of the sexually appealing voice. METHOD Two hundred adults (100 men and 100 women) in the age range of 18-24 years were asked to narrate a topic, which was recorded directly onto Computerized Speech Lab (CSL) 6103 hardware. Recorded stimuli were presented to the six judges, and they were asked to indicate if the voice is sexually appealing on a five-point rating scale. The voices, which are consistently identified as sexually very attractive and unattractive were subjected to cepstral analysis through CSL. RESULTS The results of perceptual analysis revealed that 28 of the female voice samples and 39 of the male voice samples were rated as sexually attractive. These ratings were consistent within and across the judges. The cepstral analysis was then performed in all the voice samples and the results of independent t test revealed higher values of cepstral peak parameter (CPP) in the sexually attractive voices in comparison to the other voice samples in both the genders. The obtained results are discussed with respect to the harmonic organization in the voice samples. CONCLUSIONS The results of cepstral analysis in sexually attractive voices revealed higher values of CPP in comparison to the voices rated as sexually not appealing. This could be because of the presence of well-defined harmonic structure evidenced in the sexually appealing voice in comparison to voices rated as very unappealing. Our findings suggest that cepstral analysis is a good indicator of sexually appealing voice.

Voice in chronic hemodialyzed individuals

OBJECTIVE Chronic hemodialysis affects various body systems, one of which is the respiratory system. Since respiration is the prime source for speech, vocal dysfunctions are expected to be present in patients with chronic hemodialysis. The present study attempts to shed light on the changes in acoustic and aerodynamic characteristics of voice, if any, in patients with chronic hemodialysis. MATERIALS AND METHODS Phonation of sustained vowel/a/sample was subjected to acoustic analysis using VAGHMI software. Sustained duration of/a/,/s/, and/z/ was recorded for the purpose of aerodynamic analysis. The independent t test was employed to find the significant difference between the two groups. RESULTS Chronic hemodialyzed subjects showed significant deviation in frequency, perturbation, and aerodynamic measures when compared to normal subjects. These results are discussed with respect to the underlying pathophysiology. CONCLUSION The results of the present study revealed that subjects with chronic hemodialysis exhibit clinical evidence of voice disorders. Vocal deviations in chronic hemodialyzed subjects are explained due to the influence of the renal system on the respiratory and the phonatory system and the negative fluid balance effect of hemodialysis.

Nasal airflow monitoring during swallowing: Evidences for respiratory-swallowing incoordination in individuals with chronic obstructive pulmonary disease

Background: Respiratory swallowing coordination is regarded as one of the several mechanisms by which the airway is protected from aspiration during swallowing. A lack of reciprocity between respiration and swallowing has been indicated as one of the mechanisms that can lead to aspiration and pneumonia. Since chronic obstructive pulmonary disease (COPD) is a pulmonary condition, we have hypothesized that there would be deficits observed in respiratory-swallow coordination in individuals with COPD. Hence, the present study was planned to investigate the respiratory-swallow coordination in individuals with COPD. Methods: Thirty-two individuals with the diagnosis of COPD and 32 normal controls were recruited for the study. Respiratory coordination for swallowing was measured using Kay Digital Swallowing Workstation. The specific swallowing tasks were recorded for each individual which was dry swallow, thin liquid swallow, and thick liquid swallow. Results: The results revealed that there was a significant difference between individuals with COPD and normal controls indicating that swallow apnea duration is prolonged in individuals with COPD. It was also observed that expiration-inspiration is the predominant pattern, followed by expiration-expiration, inspiration-expiration, and inspiration-inspiration in individuals with COPD when compared to predominant expiration-expiration swallow in normal controls followed by expiration-inspiration, inspiration-expiration, and inspiration-inspiration. Conclusion: The results of the present study gave an insight into the pattern of respiratory-swallowing coordination in individuals with COPD.

Does Cerebral Hemispheric Laterality Control Swallow Performance

Objectives It is well established that the brainstem regulates the act of swallow. However, the role of cortex and its influence on swallowing are still a question. Hence, the present study aimed to investigate if cerebral hemispheric laterality controls swallow activity. Methods Thirty normal right handed participants were subjected to time test of swallow using 100 ml of water. Dual paradigm was used to investigate hemispheric laterality for swallowing which involved listening to the speech or music stimuli presented binaurally while swallowing. The clinician measured total time taken and hyolaryngeal movement simultaneously which was used to calculate volume/time, volume/swallow, and time/swallow on an offline basis. Results Results revealed that swallow performance decreased with the dual task paradigm compared to baseline swallow. These results are suggestive of cortex playing a role during swallowing in the dual task paradigm. Moreover, quantitative parameters like volume/swallow and volume/time were affected more when speech was competing with swallowing. However, music exerted greater interference over the speech for time/swallow. Conclusions These results suggests that there exists differential cue lateralization hypothesis which means volume related parameters are controlled by left hemisphere and time related swallowing parameters are controlled at the right hemisphere.

Cepstral analysis of voice in healthy aged individuals

Introduction: The anatomical and physiological changes in the phonatory system due to aging have a major impact on voice. Widely researched parameters of voice such as fundamental frequency and the perturbation measures depend on the location of the exact pitch pulses, and it may yield unreliable results in case of a severely aperiodic voice. Aim of the Study: The present study focused on determining the cepstral characteristics of voice in healthy aging individuals. Methods: All the participants among the young adults, middle-aged adults, and old adults were required to sustain the vowel/a/. Voice samples were analyzed using Hillenbrand′s Z tool software to obtain the cepstral measures. Results: Results showed that there was an increase in the cepstral measures with aging, thus suggesting that the harmonic structure of voice is not affected in healthy aged individuals. Gender also influences the cepstral measures in healthy aging population. Conclusion: The results of the present study could be used by the voice clinicians while assessing adults with voice disorders. It will also help the clinicians in delineating the age and gender differences in the vocal parameters.

Respiratory swallowing coordination in healthy term neonates during the first 4 days of life

Background: This is a cross-sectional, observational study evaluating the coordination between respiration and swallowing in 22 healthy term neonates from birth to 4 days of age. Methods: Respiratory swallowing coordination was measured using Kay digital swallowing workstation by placing the nasal cannula at the entrance of the nares during breast feeding. Swallowing apnea duration (SAD) as well as the percentage of distribution of swallows in each respiratory phase such as mid-expiration (EE), shift from inspiration to expiration (IE), shift from expiration to inspiration (EI), and mid-inspiration (II) was evaluated. Results: Results showed that SAD in neonates is lesser than that of adults. Neonates preferentially swallowed at mid-expiratory phase which was followed by the transition among IE, EI, and the mid-inspiratory phases. The predominant respiratory swallow phase seen in neonates is same as that of adults. Conclusion: The findings of the objectives of the study gave insight about the temporal relation between respiration and swallowing in neonates and forms the basis for comparison against disordered respiratory swallowing coordination in neonates at a risk for dysphagia.

Speech Motor Control in Children with Downs Syndrome: Evidences from Formant Centralization Ratio

Introduction : Studies have highlighted the sensitivity of Formant centralization ratio (FCR) in the identification of vowel centralization. Since children with Downs Syndrome (DS) are found to exhibit imprecise articulation, the present study aimed at evaluating whether children with DS exhibit vowel centralization using FCR. Method : The study included 30 children with Downs syndrome and 30 healthy age and gender matched controls in the age range of 6-8 years. Materials consisted of 9 words with three vowels (/i/, /u/, and /a/) in the initial, medial, and the final word positions respectively. First and second formant frequency values were extracted using PRAAT software. The vowel-formant data (e.g., frequency of F1, F2 etc.) were separately averaged for each child and then the FCR was constructed from these averages using the formula (F2u+F2a+F1i+F1u) / (F2i+F1a). Independent t-test was employed to find out the significance of difference between the means of the two groups. Results : The results of Independent t-test revealed significant difference between the mean FCR of both the groups at t= 8.535, p < 0.00 indicating higher FCR values in children with Downs syndrome in comparison to typically developing peers. Conclusion : The results of the present study indicated that FCR obtained from both the groups vary significantly, thereby indicating that the vowel production in children with Downs syndrome may be subjected to vowel centralization. The present findings suggest the potential abilities of FCR metric in identifying vowel errors without characterizing the nature of vowel abnormalities and hence this metric should be used in the clinical population with caution.

Does obesity cause precocious pubertal voice changes in adolescent boys: Evaluating the critical weight hypothesis in the Indian adolescents

Objectives: The present study was taken up with the aim of investigating the effect of obesity and underweight on the occurrence of vocal mutation in adolescent boys. Materials and Methods: The study followed a cross-sectional study design. Ninety male participants in the age range of 14-17 years were classified into three groups based on the body mass index (BMI) which include underweight, normal weight, overweight/obese. Praat software (version 5.1.43) was used for the analysis of voice samples and speaking fundamental frequency was extracted from all the samples. Results: The results of the present study revealed significant main effect of the group (F = 5.732; P < 0.05). Results of post hoc analysis revealed that there was a significant difference between all the three groups at P < 0.05. Conclusion: The present study investigated the effect of BMI values on the occurrence of vocal mutation in the age range of 14-17 years in adolescent boys. The results revealed that obesity and underweight caused delay in the attainment of vocal mutation in the male adolescents. Hence, the present study does not favor the critical weight hypothesis at least in the vocal mutation in the Indian male adolescents.

Nonlinear dynamic analysis of voice: A normative study in the Indian population -

Background: The aim of this study was to establish normative data for the Indian population using Nonlinear dynamic analysis. In this study, correlation dimension, a measure of nonlinear dynamic analysis was performed for normophonic young, middle aged and elderly voices. Materials and Methods: For this purpose, normophonic young, middle aged and elderly individuals were selected without a history of voice/respiratory problems and vocal abuse/ misuse. 60 participants were selected in each group. All of these individuals had a normal voice as evaluated through GRBAS scale. Sound Recorder, on a computer desktop was used for voice recording and “convert” code in MATLAB as well as D2.ini.writer software based on TISEAN package (Hegger, Kantz & Schreiber, 1999) was used for the calculation of Correlation dimension (D2). Correlation dimension measures were obtained for each participant, for both steady vowel phonations (/a/, /i/, /u/) as well as narration samples. Results: The correlation dimension measures across the group revealed a significant main effect of the groups indicating correlation dimension increases with increase in age. Conclusions: The application of nonlinear dynamic measures in the assessment of voice is a novel venture and thus this study provides normative data for correlation dimensions in the Indian population for future comparisons against the disordered voice samples. Further studies are warranted to investigate the same in the clinical population. Also other nonlinear dynamic analysis methods need to be investigated to obtain the normative data in the Indian population.