• Phonetics and Speech Sciences
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• v.1 no.2
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• pp.37-42
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• 2009

The purpose of the present study was to determine the effect of the management program known as vocal function exercise (VFE) on voice quality. Typical VFE was modified and applied to patients with vocal nodules by controlling intensity of voice and relieving the vocal fold to solve hyperfunctional problems in VFE. Eight female subjects aged between 28 and 54 who had been diagnosed with vocal nodules took part in the study. The patients performed VFEs once a week for eight weeks. Vocal function exercises consist of voice hygiene, respiratory training, phonation training, and glide training. The subjects' voices were analyzed pre and post therapy on the aspects of acoustics, maximum phonation time (MPT), GRBAS, and voice handicap index (VHI). As a result, it was found that fundamental frequency ($F_o$) was significant increased, shimmer decreased remarkably and that noise to harmonic ratio (NHR) lowered obviously in the acoustic parameter. In addition, MPT was increased significantly. The scale of GRBAS indicated significant improvement in grade, roughness, and strained voice. VHI indicated significant improvement in an emotional part. In conclusion, VFE was effective in improving voice quality for patients with vocal nodules.

• Phonetics and Speech Sciences
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• v.8 no.4
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• pp.89-95
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• 2016

The purpose of this work is to analyze and synthesize the pseudo-periodicity of voice using a source model. A speech signal has periodic characteristics; however, it is not completely periodic. While periodicity contributes significantly to the production of prosody, emotional status, etc., pseudo-periodicity contributes to the distinctions between normal and abnormal status, the naturalness of normal speech, etc. Measurement of pseudo-periodicity is typically performed through parameters such as jitter and shimmer. For studying the pseudo-periodic nature of voice in a controlled environment, through collected natural voice, we can only observe the distributions of the parameters, which are limited by the size of collected data. If we can generate voice samples in a controlled manner, experiments that are more diverse can be conducted. In this study, the probability distributions of vowel pitch variation are obtained from the speech signal. Based on the probability distribution of vocal folds, pulses with a designated jitter value are synthesized. Then, the target and re-analyzed jitter values are compared to check the validity of the method. It was found that the jitter synthesis method is useful for normal voice synthesis.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.12 no.2
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• pp.140-144
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• 2001

Backgrounds & Objectives : Prolonged hearing loss was considered as one of the factors which have the potential to cause vocal changes. However, the analysis of quality of phonation in hearing loss patients has not been achieved enough. The purpose of the study was to evaluate the difference in objective acoustic parameters between long-term hearing impaired patients and normal control group. Material & Methods : The material of this investigation comprised a group of 20 patients (M : F=10 : 10) with moderate or profound hearing loss(over 50dB). The duration of all hearing loss was over 1 year. All of them underwent the acoustic examinations comprising electroglottography, multidimensional voice program and formant analysis during phonation of the bowels /a/ with free confortable tone and /i/ with voluntary high tone. The results of the acoustic examinations were compared with those of a control group, composed of 20 sex- and age-matched normal hearing subjects. Results : In the male hearing loss subjects, the significant increase was detected in pitch and shimmer during phonation of /a/ and in pitch during phonation of /i/. In addition, this group was characterized by decreased fundamental frequency during phonation of /i/. In female, there was no difference between hearing loss group and normal control group except a decreased formant 1 frequency. Conclusion : Long-term moderate and profound sensorineural hearing loss could affect the objective voice parameters.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.12 no.2
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• pp.133-139
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• 2001

Background and Objectives : There are so many methods to investigate the causes of voice disorders. However, they were almost invasive or non-physiologic methods. And none of them showed the laryngeal movements. Phonation pharyngogram is non-invasive method to see the laryngeal movement directly. Authors studied to evaluate the availability of phonation pharyngogram in laryngeal nodule. Materials and Methods : 30 laryngeal nodules and 10 control groups were evaluated. Acoustic analysis and maximum phonation time were measured and pharyngogram was taken during sustaining /a/ phonation immediately after swallowing the barium. We measured the width of hypopharyngeal wall, shape of hypopharyngeal wall and pyriform sinus apex, level difference between both true vocal folds, angle of subglottis, location of true vocal folds, elevated distance of vocal folds and shape of c-spine. Results : Jitter, Shimmer of laryngeal nodule were higher than control group and maximum phonation time was shorter in laryngeal nodule. There was a significance in width of hypopharyngeal wall, shape of pyriform sinus apex, level difference between both true vocal folds, elevated distance of vocal folds and shape of c-spine. Conclusions : Authors knew that there were differences when we used the phonation pharyngogram between normal group and laryngeal nodule group.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.8 no.1
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• pp.38-43
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• 1997

Backgroud : Now a days, most studies for professional voice user have been performed after artificial voice abuse without consideration of environmental and personal factors, and occupational specificity, therefore those studies have some problems. Objectives : To make a basic guideline for the management of untrained professional voice user, practically we ananalyzed the voice of experimental group. Materials and methods : Just after working, the sustained vowel sounds of the 15 female telephone operators (subjective group) and the 20 normal female persons (control group) were analysed, using a history paper, acoustic analyzer and videostroboscopy. Results : The most common symptom in subjective group was dysphonia. Stroboscopic findings in subjective group were as following ; posterior chink 11 cases (73%), incomplete closure 2 cases (13%), anterior chink 1 case (7%). The mean maximal phonation time in telephone operators was 12.8 seconds and in control group was 16.8 seconds. Jitter, pitch pertubation quotient (PPQ), shimmer and amplitude pertubation quotient (ASQ) were significantly increased in subjective group than control group, but there is no difference between two group in fundamental frequency and noise to harmonic ratio. Conclusion : Untrained professional voice user needs professional career guidance and counseling. And when we manage the untrained professional voice user, we should consider specific occupational, personal and environmental factors as well as laryngeal factors.

• Phonetics and Speech Sciences
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• v.3 no.2
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• pp.99-105
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• 2011

The treatment for patients with mutational dysphonia typically is useful with vegetative phonation, but has not yet been studied. This study attempts to identify the effect of $SKTCLP^{(R)}$ using throat clearing and laughing in patients with mutational dysphonia. The study, which was designed by the author, included 26 patients aged from 14 to 32 years (mean: 18.7 years) who had been diagnosed with mutational dysphonia between January 2007 and June 2010. Voice therapy for these patients included $SKTCLP^{(R)}$, ranging from two to seven sessions (mean: 3.8 sessions). Results were evaluated by videostroboscopy, perceptual evaluation of GRBAS scale, aerodynamic test, and acoustic analysis before and after therapy. Most patients could phonate with low pitch from the beginning and sustain with normal pitch sound in the last session. We had found that glottic gap reduced after therapy and anterior-posterior compression of superior laryngeal part at the first time, and these patients had complete closure of the glottis after treatment. The results of acoustic and aerodynamic measures after treatment indicated significant decreases in Fo, Jitter, Shimmer, SFF, and SPI, and increases in MPT, Psub, and vocal efficiency (p<.05). $SKTCLP^{(R)}$ may be a useful treatment method in managing mutational dysphonia. We can suggest this technique may be useful in improving the voice quality of other functional dysphonia having glottal chink or functional aphonia.

• Speech Sciences
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• v.8 no.2
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• pp.39-48
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• 2001

The purpose of this study was to examine changes in acoustic characteristics after drinking alcoholic beverages and singing in order to establish guidelines for vocal hygiene of both singers and non-singers. 21 university students (10 males and 11 females) vocalized /a/ before drinking, after drinking and after singing. Changes in vocal range and acoustic characteristics were analyzed by Dr. Speech 4.0 (Tigers Electronics). No significant difference was observed in vocal range following drinking. However, there was statistically significant changes in vocal range after singing. We may infer that appropriate amount of singing functioning as vocal warm-up, rather than drinking alone, resulted in improvement in their abilities to lengthen vocal folds. This is directly related to the ability to produce high-pitched sounds. Changes in jitter in female voices after singing was the only acoustic factor that was significant. Changes in Shimmer and NNE was not significant either after drinking nor singing. Subjects who were judged to perform better in singing were marked by minimum acoustic changes, which may due to their well-trained vocal fold function. The results of this study may address the necessity for vocal function exercises for the patients with neurogenic voice disorders including dysarthria. The need for more extensive research with a larger number of subjects including professional voice users is also addressed.

• Phonetics and Speech Sciences
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• v.7 no.4
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• pp.77-83
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• 2015

Voice complication without the laryngeal nerve injury can occur after thyroidectomy. The purpose of this study is to investigate voice changes according to extent of thyroidectomy with acoustic analysis. Thirty-five female patients with papillary thyroid carcinoma took voice evaluation at before and 1 month, and 3 months after thyroidectomy. Acoustic analysis parameters were speaking fundamental frequency(SFF), min $F_0$, max $F_0$, dynamic range $F_0$, jitter, shimmer, noise-to-harmonic ratio(NHR), and Cepstral prominence peak(CPP). Repeated-measured analysis of variance was applied. Time-related voice changes showed significant differences in all parameters except NHR. At 1 month after surgery, voice quality was worse and pitch was decreasing, but voice quality and pitch were improving at 3-month follow-up. Voice changes according to the extent of surgery were in SFF, max $F_0$, and dynamic range $F_0$. Time by surgery-related voice change existed only in min $F_0$. The result showed that the severity of voice complication depended on the extend of thyroidectomy which had a negative impact on $F_0$-related parameters. The deterioration of voice quality at 1 month after thyroidectomy may be affected by the loss of thyroid hormone in the blood. The descent of $F_0$-related parameters may be impacted by laryngeal fixation of surgical site adhesion.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.71-78
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• 2013

The purpose of this study was to compare the acoustic voice outcomes of children with cochlear implant to those of children with normal hearing. Participants were 41 children using unilateral cochlear implant (18 males and 23 females), and children with normal hearing from the same age and sex. Mean age of implantation was approximately 3 years old, mean duration of implant use was 4 years in CI group. Acoustic analyses were performed using MDVP of CSL. Speech samples were 3 sustained vowels, /a, i, u/. 9 parameters (F0, Fhi, Flo, Jitter, Shimmer, vF0, vAm, NHR, and SPI) were analyzed. Children with CI did not show the significant differences in those parameters after the vowel /a/ phonation. Meanwhile, there were significantly different results in F0, Fhi, vF0, and SPI after /i, u/ phonation. These results revealed that differences of voice characteristics in children with CI compare to children with NH persist regarding vowel context. It suggests that high vowels would recommend as speech samples for acoustic evaluation. Futhermore perceptual analysis and speech therapy for phonation control would be necessary for children with CI.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.25-32
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• 2013

This research is aimed at finding the acoustic characteristics of different voice rehabilitation techniques, the electrolaryx (EL), standard esophageal (SE), and tracheoesophageal (TE), used on 17 patients with laryngectomees. The analysis of the voice qualities was achieved using MDVP. In order to compare the acoustic characteristics, patients were asked to produce the vowel /a/ sound. The acoustic analysis included fundamental frequency (f0), jitter, shimmer, and noise-to-harmonic ratio (NHR). The main acoustic results showed no significant statistical differences between the average measurements of SE and TE speakers. It was found that the current study showed the same tendency found in previous studies. There was also a significant difference between SE and EL speakers. On the other hand, there were no significant statistical differences between the average measurements of TE and EL speakers on all acoustic measurements. This research will contribute to establishing a baseline related to speech characteristics in voice rehabilitation for patients with laryngectomees. In future, the present findings and issues should be considered in the context of gender. Specifically, the number of women who are diagnosed with laryngeal cancer continues to rise and their acoustic characteristics may indeed differ from those of men.