• Phonetics and Speech Sciences
• /
• v.4 no.2
• /
• pp.95-104
• /
• 2012

Thyroidectomy patients may have vocal paralysis or paresis, resulting in a breathy voice. The aim of this study was to investigate the aerodynamic and acoustic characteristics of a breathy voice in thyroidectomy patients. Thirty-five subjects who have vocal paralysis after thyroidectomy participated in this study. According to perceptual judgements by three speech pathologists and one phonetic scholar, subjects were divided into two groups: breathy voice group (n = 21) and non-breathy voice group (n = 14). Aerodynamic analysis was conducted by three tasks (Voicing Efficiency, Maximum Sustained Phonation, Vital Capacity) and acoustic analysis was measured during Maximum Sustained Phonation task. The breathy voice group had significantly higher subglottal pressure and more pathological voice characteristics than the non breathy voice group. Showing 94.1% classification accuracy in result logistic regression of aerodynamic analysis, the predictor parameters for breathiness were maximum sound pressure level, sound pressure level range, phonation time of Maximum Sustained Phonation task and Pitch range, peak air pressure, and mean peak air pressure of Voicing Efficiency task. Classification accuracy of acoustic logistic regression was 88.6%, and five frequency perturbation parameters were shown as predictors. Vocal paralysis creates air turbulence at the glottis. It fluctuates frequency-related parameters and increases aspiration in high frequency areas. These changes determine perceptual breathiness.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.28 no.1
• /
• pp.14-16
• /
• 2017

Pop singers frequently use breathy voice to express diverse emotion. Such method is the major factor that divides vocalization in pop and classical music. Using breathy voice too much for a long time could make singer short-winded, which might cause the voice injured. In order to prevent the problem, singers need to find resonance balance between high notes and low notes and among vowels. Moreover, they should take more attention when producing resonance in consonants with much air flow. Along with finding resonance balance, if skilled at controlling the volume of voice, singers can use the breathy voice selectively at the desired part, adjusting close quotient freely. Through this kind of approach, pop singers can develope their unique style of vocalization and avoid the vocal damage.

• Phonetics and Speech Sciences
• /
• v.4 no.2
• /
• pp.89-94
• /
• 2012

The aim of this study is to investigate the usefulness of the parameter CPP (cepstral peak prominence) and LTAS (long term average spectrum) band energy for an analysis of breathy voice with vocal fold paralysis. Thirty-four female subjects who have vocal paralysis after thyroidectomy participated in this study. According to the perceptual judgements by three speech pathologists and one phonetic scholar, subjects were divided into two groups: breathy voice group (n = 21) and non-breathy voice group (n = 13). Maximum sustained phonation task was measured for acoustic analysis. CPP-related (i.e. mean F0, mean CPP, and mean CPPs) and LTAS-related (i.e. minimum, maximum, and mean) parameters were used. Independent samples t-test was conducted. Regarding CPP, there are significant differences in mean CPP and mean CPPs between groups. The values of mean CPP and CPPs in the non-breathy voice group are higher than those in the breathy voice group. The CPP could be regarded as the useful parameter for breathy voice analysis in the clinic. When it comes to LTAS, energy from 0 to 2 kHz are significantly different between groups. The minimum value of non-breathy group is lower than that of breathy group, whereas the maximum value of non-breathy group is higher. The frequency band below 2 kHz seems to be related to breathy voice.

• Phonetics and Speech Sciences
• /
• v.9 no.4
• /
• pp.51-57
• /
• 2017

The current study compared the acoustic features of the two phonation types for Korean fricatives (plain: /s/, fortis : /s'/) and the three types for affricates (aspirated : /$ts^h$/, lenis : /ts/, and fortis : /ts'/) in order to determine the phonetic status of the plain fricative /s/. Considering the different manners of articulation between fricatives and affricates, we examined four acoustic parameters (rise time, intensity, fundamental frequency, and Cepstral Peak Prominence (CPP) values) of the 20 Korean native speakers' productions. The results showed that unlike Korean affricates, F0 cannot distinguish two fricatives, and voice quality (CPP values) only distinguishes phonation types of Korean fricatives and affricates by grouping non-fortis sibilants together. Therefore, based on the similarity found in /$ts^h$/ and /ts/ and the idiosyncratic pattern found in /s/, this research concludes that non-fortis fricative /s/ cannot be categorized as belonging to either phonation type.

• Phonetics and Speech Sciences
• /
• v.4 no.4
• /
• pp.147-154
• /
• 2012

The purpose of this study is to examine the effect of voice improvement when vocal training, which relaxes the vocal contact, is applied to children with vocal nodules. Subjects included 20 5- to 12-year-old boys with vocal nodules in Otolaryngology and for whom voice therapy had been advised. The vocal therapy was conducted for 40 minutes per a week for a total of eight times. Results were evaluated by videostroboscopy, auditory-perceptual evaluation of GRBAS Scale, aerodynamic test, and acoustic analysis before and after therapy. As a result, first, the size of vocal nodules was reduced and the unstable pattern of vocal contact was improved. Glottic closure was increased and Phase symmetry was decreased during vocal vibration. Mucosal wave was increased and muscle tension of the larynx was reduced. Second, auditory-perceptual evaluation showed that subjects' overall quality of voice improved. GRBAS Scale Evaluation showed that the characteristics of the subjects' voice which were rough, breathy, and strained and breathy were reduced after therapy. Third, the measurements of acoustic parameters showed a statistically significant improvement. The fundamental frequency of the subejects' voice was increased and values of Jitter and Shimmer, NHR, [H1-H2] decreased. Fourth, the maximum phonation time of children was increased. These results imply that vocal relaxation training conducted in this study has a very positive effect to improve the voice of children with vocal nodules.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.22 no.1
• /
• pp.40-46
• /
• 2011

Background and Objectives : Vocal fold bowing is an organic voice disorder that is associated with an abnormal structure of the vocal folds whereas vocal fold polyp is a functional voice disorder caused by an abnormal use of the vocal folds. Both types of vocal folds share a common property in that they make one's voice breathy or strained. The purpose of this study is to compare voice from two types of vocal folds and to offer information of clinical importance. Materials and Method: Vocal fold bowing and vocal fold polyp groups consisted of 7 male subjects, respectively. All subjects recorded /a/ in the state of measuring MPT (maximum phonation time), repeating 3 times, by a voice recorder (48 kHz sampling rate; 24 bit quantization). They answered the questions of K-VHI. Time domain parameters (such as perturbation parameters including HNR, Jitter, etc.) were calculated for the whole duration of /a/ and those of the frequency domain were measured in initial 40 ms and stable 40 ms of /a/, respectively. Mann-Whitney V-test was used for the time domain parameters and K-VHI survey, and Wilcoxon signed rank test was applied to the frequency domain parameters (H1, H2, H1-H2). Results: For K-VHI survey and the time domain analysis, there was no significant difference between bowing and polyp group. For frequency domain analysis, H1 and H2 showed a significantly different result between two groups. Vocal fold bowing group has longer duration and lower intensity than that of vocal fold polyp group in the 'aspirated interval', which could be observable prior to ordinary vowel oscillation. Conclusion: Both groups seem to show breathy voice. This could be referred on the basis of the value of H1-H2. The K-VHI survey says that subjects with vocal fold bowing feel more uncomfortable than subjects with vocal fold polyp.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.21 no.2
• /
• pp.121-127
• /
• 2010

Background and Objectives : Unilateral vocal fold paralysis is generally treated using injection laryngoplasty or voice therapy. However, the decision of treatment method is dependent on clinician's preference and hospital facilities without specific criteria. The purpose of the study was to examine factors predictive of voice therapy outcome in patients with unilateral vocal fold paralysis. Materials and Method : 38 patients diagnosed as unilateral vocal fold paralysis, aged from 24 to 81 years and undergone voice therapy more than 1 month were included. After 3 to 12 (mean 5.1) sessions of voice therapy, subjects had divided into responder group (RG, 28 patients) and non-responder group (NRG, 10 patients) according to G scale change. Paramters of perceptual assessment, acoustic and aerodynamic measure, and videostroboscopy were compared between two groups, and factors predictive of voice therapy result were analyzed. Results : RG patients showed significantly reduced rough, breathy, asthenic voice after voice therapy. Change of MPT and MFR was more substantial in RG than in NRG. By videostroboscopy, RG patients showed significantly more mucosal wave symmetry, glottal closure, reduced glottal gap index during the closed phase of phonation, while NRG patients showed more occurrences of abnomal supraglottic activities during phonation (p < 0.05). Poor outcome of voice therapy significantly associated with increased asthenic scale, short MPT, and less glottal closure (p=0.02). In addition, 90% of patients with MPT more than 5 seconds were in RG, whereas 56% of patients with MPT less than 5 secondes were in RG. Conclusion : Voice therapy is useful for large proportion of patients with unilateral vocal fold paralysis as an initial treatment method. However, patients with large asthenia scale, large glottic gap or MPT less than 5 seconds tend to have poor voice therapy outcome, and early injection laryngoplasty maybe recommended for these patients.

• Phonetics and Speech Sciences
• /
• v.3 no.3
• /
• pp.133-140
• /
• 2011

Muscle misuse dysphonia (MMD) is defined as a behavioral voice disorder resulting from inappropriate contractions of intrinsic and/or extrinsic laryngeal muscles. The purpose of this study was to investigate the effect of motor learning guided laryngeal motor control therapy (MLG-LMCT) which is designed to improve an existing LMT and further the effective voice treatment on people with muscle misuse dysphonia. Forty-six people with MMD (M:F=16:30) participated in this study. The voice samples of the participants were recorded to investigate the effect of MLG-LMCT before and after the voice therapy. Voice samples were analyzed via electro-glotto-graph (EGG). Contact quotient (CQ), speed quotient (SQ), and waveform were reported. In addition, perceptual and acoustical evaluation were conducted to determine the change of voice improvement after treatment. The experimenter massaged the tensioned muscles around the neck. In order to find more proper phonation the experimenter showed the subjects their EGG wave forms as to whether or not they are moving the vocal folds to the appropriate position. Therefore, the EGG wave forms were used as a type of visual feedback. With the wave form, the experimenter helped subjects move the vocal folds and laryngeal muscles to find more proper voice production. The sensory stimuli from the experimenter gradually faded out. A paired dependent t- test revealed that there was significant differences in CQ between pre- and post-therapy. Perceptually, overall, rough, breathy, strain, and transition were significantly reduced. Acoustically, there were significant differences in Fo, jitter, shimmer, and NHR. After using MLG-LMCT, most of the subjects showed improvements in voice quality. The results from this study led us to the following conclusions: Motor learning guided laryngeal motor control therapy (MLG-LMCT) has reduces muscle misuse dysphonia. These results may occur because a visual feedback from EGG wave form can maintain the effect of the muscle tension reduction from laryngeal manual therapy. In case of people with MMD who reduced muscle tension from the therapy (LMT) but, not appropriately manipulating the location of larynx or adducting the vocal folds, MLG-LMCT might be an alternative therapy approach.