• Phonetics and Speech Sciences
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• v.14 no.4
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• pp.11-17
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• 2022

This study investigates closure durations of Korean stops in terms of laryngeal contrasts, places of articulation, and three positions within words. Twenty-two Korean speakers produced the nonsense words containing Korean stops found in word-initial and word-final positions and between vowels. The statistical results showed that the closure durations differed significantly by laryngeal contrast and place of articulation. In addition, the differences by position within words were marginally significant. The closure durations were in the order of lenis < aspirated < fortis stops by laryngeal contrast, velar < alveolar < bilabial stops by place of articulation, and word-final < word-initial < between vowels by positions within words. The laryngeal contrasts were neutralized in word-final position as per coda neutralization in Korean phonology. This study shows that closure durations should be considered a valuable phonetic cue to identify stops on par with voice onset time and f0.

• The Korean Journal of Emergency Medical Services
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• v.21 no.3
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• pp.7-16
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• 2017

Purpose: The purpose of the study was to investigate the effects of laryngeal mask airway (LMA) insertion from different positions, using different methods, on the quality of the insertion, for identifying a more convenient and effective insertion method. Methods: In a model ambulance, 30 paramedic students performed the LMA insertion procedure, in four different settings, combinations of the rescuer's position (at the head end of the patient, at the side of the patient), and insertion technique (index finger insertion, thumb insertion), in a randomized order. Quality of insertion index and convenience of use were measured. Results: The quality of insertion index (tidal volume, gastric insufflation, airway pressure, airway sealing pressure, midline positions, insertion success grade, and insertion time) were not significantly different among four different settings. However LMA insertion from the anterior (head) end, using the index finger method compared to the thumb method was found to be significantly more convenient. Conclusion: We recommend using the more convenient and familiar LMA insertion method, between index finger insertion and thumb insertion, regardless of rescuer's position.

• Phonetics and Speech Sciences
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• v.14 no.2
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• pp.55-65
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• 2022

This study aimed to compare acoustic measurements by the high, middle, and low laryngeal heights of male musical theater students. Furthermore, the correlation between the relative height of the larynx and the acoustic measurements was examined, along with the predictability of the relative height (vertical position) of the larynx from acoustic measurements. The participants included five male students majoring in musical theater singing, and acoustic analysis was performed by having them produce the /a/ vowel 10 times each at the laryngeal positions of high, middle, and low. The relative vertical positions of the laryngeal prominence in each position were measured based on the resting position. Results indicated that the relative position of the larynx varied significantly according to laryngeal height, such that as the larynx descended, the first three formant frequencies decreased while the spectral energy at the same frequencies increased. Formant frequencies showed a weak to moderate positive correlation with the relative height of the larynx, while the spectral energy showed a moderate negative correlation. The relative height of the larynx was predicted by eight acoustic measures (adjusted R² = .829). In conclusion, the predictability of the relative height of the larynx was partially confirmed in a non-invasive manner.

• The Korean Journal of Nuclear Medicine
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• v.32 no.3
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• pp.276-289
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• 1998

Purpose: To evaluate dysphagia objectively and quantitatively, and to clarify the effect of neck position and viscosity changes in patients with aspiration and laryngeal penetration. Materials and Methods: We studied 35 patients with dysphagia and 21 normal controls using videofluoroscopy and scintigraphy. Videofluoroscopy was performed with barium with three different viscosity, and scintigraphy was done with water, yogurt, and steamed egg mixed with Tc-99m tin colloid. If aspiration was found during videofluoroscopic examination, patient's neck position was changed and study repeated. Videofluoroscopy was analyzed qualitatively. We calculated 7 quantitative parameters from scintigraphy. According to the videofluoroscopic findings, we divided patients into 3 subgroups; aspiration, laryngeal penetration, and no-aspiration group. Results: The result of videofluoroscopy revealed that the most common finding was the delay in triggering pharyngeal swallow. Pharyngeal transit time (PTT) and pharyngeal swallowing efficiency(PSE) in patients with aspiration were signifi-cantly different from other groups. After neck position change, aspiration could be reduced in all of 7 patients, and laryngeal penetration reduced by about 82%. PTT and PSE were also improved after position change. Aspiration and laryngeal penetration occurred more frequently in thin liquid swallowing than in thick liquid and solid swallowing. Conclusion: PTT and PSE were useful for the evaluation of dysphagia. Aspiration and laryngeal penetration could be reduced when appropriate position assumed. We could decrease the chance of aspiration by changing the patient diet consistency. Scintigraphy might be useful tool to quantitate and follow up these changes.

• Phonetics and Speech Sciences
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• v.2 no.3
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• pp.91-99
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• 2010

This paper reports on an identification test where KFL learners identified the Korean three-way laryngeal contrast in the phrase-initial position, when the phrase-initial tone was systematically manipulated. It turns out that heritage learners have some sensitivity to phrase-initial tone and show a plain-aspirated alternation in their identification according to the phrase-initial tone, as native speakers do, whereas non-heritage students do not show such tone sensitivity. However, after a weekly prosody training, second-year non-heritage students have shown a significant improvement in their performance. This paper clearly shows that the phrase-initial tone plays a critical role in distinguishing laryngeal features of Korean obstruents, and also suggests that prosody including the tone-segment correlation should be incorporated in the KFL curriculum.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.24 no.2
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• pp.96-101
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• 2013

Laryngeal framework surgery (LFS) is a unique phonosurgical concept that enables us to influence the laryngeal biomechanics by changing the shape/position of the laryngeal cartilages. LFS procedures can be favorably combined with one another but also with other phonosurgical methods, and they are usually reversible and correctable. Type I thyroplasty and arytenoid adduction are still useful in spite of the recent popularity of injection laryngoplasty. Basic surgical principles have seldom been changed since Isshiki's development, but a number of modifications have been tried and are still going on. These delicate surgeries require exhaustive training, but the reward is great to both the surgeon and the patient.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.33 no.2
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• pp.59-63
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• 2022

The laryngeal framework surgery (LFS) is an operation to correct the position and tension of the vocal cords by changing the laryngeal cartilage and muscles. LFS such as type 1 thyroplasty, arytenoid adduction, and arytenopexy is performed to improve the voice of patients with unilateral vocal cord paralysis. It is known that the voice improvement effect of LFS in patients with unilateral vocal cord paralysis is excellent and lasts for a long time. LFS can also be operated under local anesthesia. Complications are not common, however, severe complications like airway obstruction could occur after the operation. Recently, several other attempts to modify the traditional surgical method have been reported. This review is intended to be helpful in understanding the characteristics and changes in laryngeal framework surgery.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.31 no.1
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• pp.31-34
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• 2020

Tracheostomy is considered as a first treatment, when oral intubation seems to be difficult in patient who present severe upper airway obstruction. Generally, tracheostomy is performed in supine position. But if airway obstruction is severe enough to cause dyspnea, low oxygen saturation and inability to maintain supine position, tracheostomy should be performed in sitting position. The authors report a case of successful tracheostomy using high flow nasal cannula which help to maintain stable oxygen saturation and respiration in patients with laryngeal cancer.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.16 no.1
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• pp.53-67
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• 2005

It is known that Korean stop consonants in syllable-initial position are of three types : lax, aspirated and forced (or unaspirated). In syllable-final position, however, these three different types are merged to a single type with the same place of articulation, although the original three-way distinction is preserved in Korean orthographic (Hangul) system. Thus the syllable-final stops are phonetically realized as voiceless "applosives" which are characterized by the absence of oral release. The aim of the present study is to investigate the laryngeal adjustments for these syllable-final stops in various phonological conditions by using fiberscope, and, is to further investigate electromyographically the laryngeal adjustments for Korean stops both in the syllable-initial and final positions in various phonological conditions. The results can be summarized as follows : 1. In the case of syllable-initial stops, the glottal widths in each three types of the Korean stops during the articulatory closure are clearly different. And the pattern of thyroarytenoid(VOC) activity appeared to characterize the three different types of Korean stops. 2. The basic laryngeal feature of the Korean syllable-final applosives is characterized by a small degree of glottal opening which begins at or slightly after the oral closure. 3. In the case, syllable-final stop followed by the copula "ita", the syllable- final stop is pronounced as the stop consonant at the initial position of the following syllable containing the vowel[i], the underlying features of three-way distinction for the stops in the Korean orthographic(Hangul) system being manifested at the laryngeal adjustment. 4. In the case of the final applosives followed by the initial stops and fricatives, the laryngeal feature of the final applosives appears to be assimilated by that of the following consonant irrespective of the difference in the place of articulation, as far as the glottal abduction/adduction is concerned. It is clearly demonstrated in the case of syllable-initial stop that thyoarytenoid(VOC) activity is suppressed for the production of the stop consonants in question, the degree of which is slightest for the forced type and most marked for the aspirated type, while it is moderate for the lax type.

• Archives of Craniofacial Surgery
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• v.18 no.4
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• pp.223-229
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• 2017

The beauty of the laryngeal mask is that it forms an air tight seal enclosing the larynx rather than plugging the pharynx, and avoid airway obstruction in the oropharynx. The goal of its development was to create an intermediate form of airway management face mask and endotracheal tube. Indication for its use includes any procedure that would normally involve the use of a face mask. The laryngeal mask airway was designed as a new concept in airway management and has been gaining a firm position in anesthetic practice. Despite wide spread use the definitive role of the laryngeal mask airway is yet to be established. In some situations, such as after failed tracheal intubation or in oral surgery its use is controversial. There are several unresolved issues, for example the effect of the laryngeal mask on regurgitation and whether or not cricoids pressure prevents placement of mask. We review the techniques of insertion, details of misplacement, and complications associated with use of the laryngeal mask. We then attempt to clarify the role of laryngeal mask in air way management during anesthesia, discussing the advantages and disadvantages as well as indications and contraindications of its use in oral and maxillofacial surgery.