BACKGROUND AND OBJECTIVES: Although mass transit systems are convenient and efficient for urban people, little attention has been paid to the potential hearing hazard from their noise. The purpose of the current study was to measure and analyze levels of subway interior noise at peak commuter times and to provide information about commuters' daily dose of noise exposure. MATERIALS AND METHODS: To measure the subway interior noise, nine subway lines inside Seoul (i.e., lines 1-9) and six lines surrounding the capital city area (i.e., Central, Bundang, Sinbundang, Incheon, Gyeongui, and Gyeongchun) were chosen. The noise was measured and recorded by a sound level meter for two-hour periods in the morning and evening. RESULTS: 1) In the LZeq analysis, the average noise level of all 15 lines was 72.78 dB; the maximum and minimum noise levels were 78.34 and 62.46 dB, respectively. The average noise level of the nine lines inside Seoul was 73.45 dB, which was 1.68-dB louder than that of the six lines surrounding the capital city area. 2) Based on the LZeq analysis of 33 measured frequencies, 12.5 Hz was the highest frequency and 20,000 Hz was the lowest. 3) There was no remarkable difference in the level of subway interior noise between morning and evening peak commuter times. CONCLUSIONS: We concluded that the level of subway interior noise was not loud enough for commuters to incur noise-induced hearing loss. Regardless, environmental noise control efforts in the subway system might be needed for commuters who take a subway every day.
Hearing ; Hearing Loss, Noise-Induced ; Incheon ; Noise* ; Railroads* ; Seoul

This brief communication introduced a systematic way to find a professional audiology clinic developed for patients and professionals by the American Academy of Audiology, American Speech-Language-Hearing Association, and Healthy Hearing. Patients can access each organization's website to find professionals and/or clinics based on criteria such as location, hours, special areas, types of service, reviews and rating by previous patients, and kinds of insurance accepted. Such a system may protect the patients from information overload, guarantee accurate information, and help them find themselves professional audiologists who can assist them. We expect professional organizations to adopt this system as soon as possible and link hearing-impaired patients with professional audiologists in Korea.
American Speech-Language-Hearing Association ; Audiology* ; Hearing ; Hearing Aids ; Humans ; Insurance ; Korea ; Societies

Background and Objectives: Although thyroid hormones affect human cancer progression, the regulatory mechanism of thyroid hormone receptors in carcinogenesis has not been elucidated. This study aimed to evaluate the expression pattern of the thyroid hormone receptor (TR) and its corepressors, and to investigate the clinical and biological functions of TR. Materials and Methods: Transcriptomic and clinical data for thyroid cancer were downloaded from The Cancer Genome Atlas. Paraffin-embedded tissue sections from patients who underwent thyroidectomy were used for immunohistochemistry. BCPAP cells were treated with T3 to investigate the thyroid hormone target genes. Thyroid hormone receptor alpha (THRA) and Thyroid hormone receptor beta (THRB) were knocked down by transient siRNA transfection. Results: THRA and THRB expression was lower in thyroid cancer tissues than in normal tissues. However, strong focal staining of TRβ was observed in the invasive front. High THRB expression was associated with high Silencing Mediator for Retinoid or Thyroid hormone receptor (SMRT) expression, older age, a high MACIS (distant Metastasis, patient Age, Completeness of resection, local Invasion, and tumor Size) score, more aggressive histological subtypes, more frequent extra-thyroidal extension, and advanced TNM stage. THRB expression was positively correlated with Hypoxia Inducible Factor 1 Subunit Alpha (HIF1A), L1 Cell Adhesion Molecule (L1CAM), and Lysyl Oxidase (LOX) expression. Thyroid hormone-induced HIF1A, L1CAM, and LOX upregulation was abolished by siTHRB but not siTHRA in BCPAP cells. High SMRT and high THRB groups (SMRT/THRB) presented more aggressive clinical features and showed an upregulation of HIF1A, L1CAM, and LOX, as well as of epithelial-mesenchymal transition (EMT)-related genes, causing changes in the tumor microenvironment. Conclusion Cooperative subtype switching from NCOR1/THRA to SMRT/THRB was thus related to aggressive clinical and molecular features, possibly related to EMT and EMT-related tumor microenvironment.

BACKGROUND AND OBJECTIVES: It is acknowledged that speech perceptual errors are increased in listeners who have sensorineural hearing loss as noise increases. However, there is a lack of detailed information for their error pattern. The purpose of the present study was to analyze substitution patterns of phoneme errors in Korean hearing aid (HA) and cochlear implant (CI) users who are postlingually deafened adults. SUBJECTS AND METHODS: In quiet and under two noise conditions, the phoneme errors of twenty HA and fourteen CI users were measured by using monosyllabic words, and a substitution pattern was analyzed in terms of manner of articulation. RESULTS: The results showed that both groups had a high percentage of nasal and plosive substitutions regardless of background conditions. CONCLUSIONS: This finding will provide vital information for understanding the speech perception of hearing-impaired listeners and for improving their ability to communicate when applied to auditory training.
Adult ; Cochlear Implants* ; Hearing Aids* ; Hearing Loss, Sensorineural ; Hearing* ; Humans ; Noise ; Speech Perception