• Speech Sciences
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• v.14 no.4
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• pp.251-260
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• 2007

The structure changes of the vocal folds are related to the fundamental frequencies (F0). In other words, the increasing in vocal fold length and thickness makes the result of dropping in the F0 during the mutational period. The purpose of this study was to investigate F0 of normal children's voice in mutational period. 360 children (180 boys and 180 girls) were participated in this experiment. The age was ranged from 11 to 16 years. The subjects were asked to produce sustained comer vowels (/a/ /i/ /u/) five times each and the data were analyzed using the MDVP of CSL. The result shows that the F0 are considerably decreased with age and reach to adults' F0 by 16 years in most cases. In particular, the F0 of male subjects were rapidly decreased between the ages from 12 ($226.98\;{\pm}\;19\;Hz$) to 13 years ($169.3\;{\pm}\;25\;Hz$), while the F0 of female subjects were slowly changed from the later period of 12 to 16 years old. This result may be used by the meaning of guideline and lead the basic data to differentiate between normal voice and voice disorder.

• Speech Sciences
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• v.10 no.3
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• pp.103-116
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• 2003

This study examines whether gender influences voice cessation time (voicing duration) of lax (voiced) obstruents. Females more frequently show a posterior glottal opening throughout a vibratory cycle and have larger open quotients and less vocal fold contact than males. The gender differences imply that females can yield less voicing in their speech. In line with this, we hypothesized that the male voice is more voiced than the female voice in intervocalic lax (voiced) obstruents. This hypothesis was supported by the results of the present experiment, i.e., males exhibited significantly longer voicing and higher percentage of voicing relative to consonant duration than females during the intervocalic lax obstruents /p, t, k, c/ of Korean. Based on the results and the literature review, it is further hypothesized that the vocal folds are more likely adducted for males while abducted for females. The experimental data also indicated that males speak faster than females.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.4 no.1
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• pp.12-18
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• 1991

A retrospective review of clinical records of 34 cases with polypoid vocal folds who underwent endolaryngeal microsurgery was carried out. The results were followings; 1) The incidence was high in elder age group(mean age : 53.7 years old). 2) Bilateral lesions were much more frequent than unilateral ones(67.6% vs. 32.4%). 3) Nine out of 34 patients had associated local pathologies and nine out of 34 patients had associated systemic pathologies. 4) Smoking appeared to be the most dominant predisposing factor(76.5%). 5) Maximal phonation time was decreased in 10 cases out of 14 cases(71.4%) and phonation quotient was increased in 9 cases out of 14 cases(64.3%). 6) All the cases were treated with sucking technique and the voice quality was improved in 32 cases(94.1%) The average duration for voice improvement was 2.8 months.

• Speech Sciences
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• v.7 no.3
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• pp.285-294
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• 2000

In this paper the acoustic characteristics of pathological voice, which are measured before and after surgical operation, are compared. This experiment is conducted for the purpose of predicting patients' speech after operation. The voices are recorded from the same patients. Jitter, shimmer and other parameters are. computed and their statistical characteristics are compared. Also spectral changes, such as formant frequency shift and spectral slope change, are compared. From the experimental results, it is verified that not only source characteristics but also vocal tract components vary. And this indicates that the modification of source parameters are not enough for the prediction. Also the result indicates that the operation causes change to both the physical shape of vocal folds and the manner of articulation.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.3 no.1
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• pp.22-28
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• 1989

Laryngostroboscopy is one of the most practical techniques for clinical examination of the larynx. The videostroboscopy provides valuable information concerning the nature of vocal folds' vibration, an immediate image of the presence or absence of pathology, and a permanent record. Additionally, when used by trained observers in conjunction with other instrumentation, it can provide both qualitative and quantitative data on vocal function of both the normal and disordered larynx. The authors examined the 388 patients with voice disorders by videostroboscope. This paper describes the clinical procedure of laryngostroboscopy based on some introductory remarks on laryngeal anatomy and function. And the findings of parameters observed by the stroboscopy is noted for the laryngeal disorders.

• Speech Sciences
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• v.15 no.2
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• pp.169-176
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• 2008

This study was intended to analyze difference of vocal folds movements between upon wakeup and in several hours later in the morning. The difference of vocal fold movements was compared with fundamental frequency and a range of fundamental frequencies from maximum to minimum. The participants were 30 female adults between 20 and 29 years old. Voice samples were collected from their reading sentence (Jeong, 1993). The first sampling was conducted within 5 minutes after wakeup, while the second on 1 hour after the first sampling. Finally, the third voice sample was collected on 6 hours after the second sampling. The results of this study were as follows: First, fundamental frequency of the participants were by hour significantly time-dependent(F=7.843). Post-hoc multiple comparison (LSD) was conducted to determine when the difference could be observed. The result showed significant differences between upon wakeup and 6 hours later (p< .001) and between 1 hour later and 6 hours later (p< .05). Second, there were a significantly time-dependent ranges of fundamental frequencies of participants by hour (F=3.130). According to the results of the LSD analysis the significant differences in range of fundamental frequencies were found between upon wakeup and 1 hour later and also between wakeup and 6 hours later (p< .05). The results above indicate that vocal fold movements upon wakeup is different from those of several hours later.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.28 no.2
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• pp.71-78
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• 2017

Voice disorder is classified into three categories, structural, neurogenic and functional dysphonia. Neurogenic dysphonia refers to a disruption in the nerves controlling the larynx. Common examples of this include complete or partial vocal cord paralysis, spasmodic dysphonia. Also it occurs as part of an underlying neurologic condition such as Parkinson's disease, myasthenia gravis, Lou Gehrig's disease or disorder of the central nervous system that causes involuntary movement of the vocal folds during voice production. Functional dysphonia is a voice disorder in the absence of structual or neurogenic laryngeal characteristics. A near consensus exist that Muscle tension dysphonia (MTD) is functional voice disorder wherein hyperfunctional laryngeal muscle activity whereas Spasmodic dysphonia (SD) is neurogenic, action-induced focal laryngeal dystonia including several subtype. Both Adductor type spasmodic dysphonia (AdSD) and MTD may be associated with excessive supraglottic contraction and compensation, resulting in a strained voice quality with spastic voice breaks. It makes these two disorders extremely difficult to differentiate based on clinical interpretation alone. Because treatment for AdSD and MTD are quite different, correct diagnosis is important. Clinician should be aware of the specific vocal characteristics of each disease to improve therapeutic outcome.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.30 no.1
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• pp.12-14
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• 2019

Functional dysphonia (FD) is a disease entity which includes various voice disorders in the absence of structural or neurologic laryngeal pathology. Muscle tension dysphonia (MTD), psychogenic dysphonia are representative FD with completely different pathogenesis. Therefore there is no standard treatment modality for FD, the first step of treatment of FD is differentiating patient's voice symptoms from other organic voice disorders and other functional voice problems. MTD is a functional voice disorder caused by hyperfunction of intrinsic and extrinsic laryngeal musculature. Symptoms include increased vocal effort, roughness, fatigue and odynophonia. First line for MTD is indirect or direct voice therapy. Unfortunately, many patients with MTD improve with voice therapy alone. For these patients, various modalities tried; lidocaine application, surgical excision of the false vocal folds, and botulinum toxin injection, etc. Botulinum toxin injections are widely used in the field of otolaryngology, especially for spasmodic dysphonia. However, its use in FD or MTD has only been described in few case reports. The aim of this lecture is to evaluate the feasibility of botulinum toxin injection for FD, especially MTD.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.32 no.3
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• pp.118-123
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• 2021

The pulsed photoangiolytic 532-nm potassium-titanyl-phosphate (KTP) laser has emerged in recent years as an efficacious treatment modality for vocal fold lesions. It also has broadened the indications for other laryngeal laser surgery. Features of KTP laser that it is a fiber-based delivery system and its energy is selectively absorbed by oxyhemoglobin make it suitable for office-based laryngeal procedures. An office-based KTP laser surgery provides an alternative management option for benign laryngeal diseases and can be performed comfortably under flexible endoscopic guidance which is placed through the nose of a fully awake patient. Office-based laryngeal surgery with a KTP laser can alleviate the need for general anesthesia. However, there are some limitations to apply due to reduced visual precision and the fact that the vocal folds are moving during procedures. Clinicians should carefully weigh the advantages and disadvantages of office-based procedures before a treatment option is selected. Patient selection and standardized laser energy parameters may help in decreasing complications and improving the treatment results.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.5 no.1
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• pp.11-21
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• 1994

The vocal pitch is controlled by the tension, mass, and length of the vocal fold. It is well known that cricothyroid approximation raises the vocal pitch by simulating the contraction of the cricothyroid muscle, and there were so many reports that have noted a relationship between cricothyroid distance and pitch control, but there does not seem to be any single generally accepted theory to account for this connection. It is generally known that the strap muscles are active during low and falling Fo, and the suprahyoid muscles are active during high and raising Fo. These findings can be related to a general picture of the motion of the larynx during changes in Fo, the cricothyroid joint would tend to lengthen the vocal folds, as the larynx moves up and forward, and relax them as it moves back and down. In this study, we suggest that the relationship between anterior cricothyroid distance and fundamental frequency of the larynx was so complex according to the level of larynx and vertebral curvature. The higher the level of larynx, the wider the cricothyoid distance, but there is more greater fundamental frequency even though more wide cricothyroid distance. This phono-menon seems to be due to the multifactors, especially the vertical tension of the conus elasticus or the change of cricothyroid articulation. It is generally known that the crocothyoid and vocal is muscles are very closely related to pitch elevation, but sternohyoid muscle seems to be more closely related to pitch lowering. By this electromyographic studies, the sternohyoid muscle have dual activity to pitch control, increased activity during the low fundamental frequency and falling pitch, but also increased activity during the higher fundamental frequency and raising pitch at least in this study.