Carbon-nanotube-grafted glass-fiber-reinforced composites: Synthesis and mechanical properties.

Glass fibers (GFs) are commonly used as reinforcements for advanced polymer composites. To improve the interfacial shear properties and mechanical properties of GF-reinforced composites (GFRPs), carbon nanotubes (CNTs) are directly grafted onto GFs using chemical vapor deposition (CVD). However, this process requires high temperatures, which causes thermal degradation of GFs, deteriorating their mechanical properties. In this study, a low-temperature CNT-grafting process was investigated using a bimetallic catalyst introduced onto a GF fiber surface via precursor solutions. The mechanical properties of the CNT-grafted GFs fabricated at different CVD temperatures were evaluated; they consistently showed low tensile strengths at temperatures above 400 °C. Subsequently, various CNT-grafted GFRPs were manufactured, and their mechanical properties were characterized. Interestingly, the flexural strengths of the composites increased with maintained tensile strength, despite a deterioration of the CNT-grafted GF reinforcements due to the CVD process. This could be attributed to the improved interfacial shear strength (IFSS) of the CNT-grafted GFs at the fiber level, and the enhanced compressive strength and interlaminar shear strength (ILSS) of CNT-grafted GFRPs at the composite level. Considering the properties of GF through CVD processes, particularly in relation to temperature, and factors such as IFSS, ILSS, tensile, compressive and flexural properties of composite materials, grafting CNTs on GF via a CVD system demonstrated its highest optimality at 450 °C.

In vitro and in vivo anti-pigmentation effects of 2-mercaptobenzimidazoles as nanomolar tyrosinase inhibitors on mammalian cells and zebrafish embryos: Preparation of pigment-free zebrafish embryos.

Recently, 10 2-mercaptobenzo[d]imidazole (2-MBI) compounds (1-10) were synthesized. Although all 2-MBI compounds are tyrosinase inhibitors that inhibit mushroom tyrosinase at extremely low concentrations (IC50 values: 20-740 nM) and effectively inhibit the browning of apples, to our knowledge, no studies have determined whether 2-MBI compounds inhibit mammalian tyrosinase. Mammalian tyrosinase is different from mushroom tyrosinase in its distribution within the cell and has structural characteristics that are different from mushroom tyrosinase in amino acid sequence and in the presence of a quaternary structure. Thus, the effect of the 10 2-MBI compounds on mammalian tyrosinase activity was investigated in B16F10 cells. Six compounds (1-6) exhibited stronger intracellular tyrosinase inhibition than that of kojic acid and phenylthiourea (PTU), which are known to be the most potent tyrosinase inhibitors; their strong tyrosinase inhibitory activity robustly inhibited intracellular melanin production in B16F10 cells. None of the tested 2-MBI compounds exhibited appreciable cytotoxicity in HaCaT and B16F10 cells. To confirm the anti-melanogenic efficacy of the 2-MBI compounds in vivo, a zebrafish embryo model was used. At concentrations 100 times lower than kojic acid, most 2-MBI compounds demonstrated much stronger depigmentation efficacy than that of kojic acid, and three 2-MBI compounds (2-4) showed depigmentation activity similar to or more potent than that of PTU, resulting in nearly pigment-free zebrafish embryos. These results suggest that 2-MBI compounds may be potential therapeutic agents for hyperpigmentation-related disorders.

Engineering of two thiamine diphosphate-dependent enzymes for the regioselective condensation of C1-formaldehyde into C4-erythrulose.

A number of carboligases, which catalyze condensation of C1- and/or C2-aldehydes into multi-carbon products, have been reported. However, their catalytic activities and/or regioselectivities remained rather low. Thereby, this study has focused on engineering of C1 and C2 carboligases for the regioselective condensation of C1-formaldehyde into C4-erythrulose via C2-glycolaldehyde. The crystal structure of the glyoxylate carboligase from Escherichia coli (EcGCL) was elucidated in complex with glycolaldehyde. A structure-guided rationale generated several mutants, one of whose catalytic activity reached 15.6 M-1·s-1, almost 10 times greater than the wild-type enzyme. Another variant (i.e., EcGCL_R484M/N283Q/L478M/M488L/R284K) has shown significantly increased stability to the glycolaldehyde toxicity, enabling production of glycolaldehyde to 31 mM from 75 mM formaldehyde (conversion: 83 %). Besides, the E1 subunit of α-ketoglutarate dehydrogenase complex from Vibrio vulnificus (VvSucA) was engineered as a regiospecific C2 carboligase for condensation of glycolaldehyde into erythrulose. The combination of EcGCL_R484M/N283Q/L478M/M488L/R284K and VvSucA_K228L led to the cascade production of erythrulose to 8 mM from 90 mM formaldehyde via glycolaldehyde without byproduct formation. This study will contribute to valorization of C1 gases into industrially relevant multi-carbon products in an environment-friendly way.

Rasch Analysis of the Korean Version of the Tinnitus Handicap Inventory.

Tinnitus is the perception of abnormal sounds in the ears or head without external auditory stimulation. While classical test theory is often used in tinnitus questionnaire development, it has limitations in assessing item characteristics. Item response theory (IRT) offers more precise individual ability estimations and identifies key and less important items, making it superior for reliable measurement tools. This study investigated the suitability of the Korean version of the Tinnitus Handicap Inventory (K-THI) as a patient-reported outcome measure (PROM) for clinical trials. Using Rasch analysis based on IRT, we evaluated K-THI's measurement of tinnitus-related disability in 545 patients (40.4% men, 59.6% women). Five items (2, 7, 8, 19, and 24) did not fit the Rasch model, yet a unidimensional scale and good fit for person and item data emerged (person: 0.89; item: 0.98). The three-point rating scale in K-THI proved suitable. IRT allowed precise evaluation of K-THI's properties, vital for reliable PROMs in patient-centered care. Our findings highlight IRT's role in questionnaire development, contributing to the advancement of PROMs.

Effects of Transcutaneous Trigeminal Electrical Stimulation and Sound Therapy in Patients with Tinnitus.

PURPOSE: Tinnitus is one of the most common health conditions worldwide. Although various methods of treatment have been used, the condition is still difficult to manage or cure. This study aimed to evaluate the therapeutic effects of transcutaneous trigeminal electrical stimulation (TTES) combined with notched sound therapy (NST) on patients with tinnitus. MATERIALS AND METHODS: A clinical trial was conducted prospectively from September 2020 to September 2021 at a single center in South Korea. In total, 14 patients took part in this trial. Periodic visits and tele-monitoring were used to assess treatment compliance and collect data, including electroencephalography (EEG), photoplethysmography (PPG), tinnitus handicap inventory (THI), tinnitus magnitude index, Beck Depression Inventory (BDI), Pittsburgh Sleep Quality Index (PSQI), and 36-item short-form survey (SF-36) results. RESULTS: Changes after intervention were analyzed with paired t-test. This study showed that alpha waves in the left hemisphere measured by EEG (p=0.024), autonomic nervous system balance (p=0.007), and stress level (p=0.022) measured by PPG significantly changed after intervention. Also, THI scores especially emotional symptoms (p=0.029) and catastrophic symptoms (p=0.043) decreased after treatment. The SF-36 score, both mental component summary and physical component summary score (each p<0.001), increased significantly, whereas the PSQI score (p<0.001) and BDI score (p<0.001) decreased after TTES and NST. CONCLUSION: Based on the results of our study, we could confirm that TTES combined with NST can significantly improve tinnitus, catastrophic symptoms, and the overall quality of life of patients.

One-Pot Synthesis of 1,3,4-Oxadiazines from Acylhydrazides and Allenoates.

The framework of 1,3,4-oxadiazine is crucial for numerous bioactive molecules, but only a limited number of synthetic methods have been reported for its production. In 2015, Wang's group developed a 4-(dimethylamino)pyridine (DMAP)-catalyzed [2 + 4] cycloaddition of allenoates with N-acyldiazenes, which provided an atom-efficient route for 1,3,4-oxadiazines. However, the practicality of this method was limited by the instability of N-acyldiazenes as starting materials. Building upon our ongoing research about the aerobic oxidation of hydrazides and their synthetic applications, we hypothesized that aerobic oxidative cycloadditions using acylhydrazides instead of N-acyldiazenes may provide a more practical synthetic route for 1,3,4-oxadiazines. In this manuscript, we describe a one-pot synthetic protocol for 1,3,4-oxadiazines from acylhydrazides and allenoates. The developed one-pot protocol consists of aerobic oxidations of acylhydrazides into N-acyldiazenes using NaNO2 and HNO3, followed by the DMAP-catalyzed cycloaddition of allenoate with the generated N-acyldiazenes. A variety of 1,3,4-oxadiazines were produced in good to high yields. In addition, the practicality of the developed method was demonstrated by a gram-scale synthesis of 1,3,4-oxadiazine.

PPAR Pan Agonist MHY2013 Alleviates Renal Fibrosis in a Mouse Model by Reducing Fibroblast Activation and Epithelial Inflammation.

The peroxisome proliferator-activated receptor (PPAR) nuclear receptor has been an interesting target for the treatment of chronic diseases. Although the efficacy of PPAR pan agonists in several metabolic diseases has been well studied, the effect of PPAR pan agonists on kidney fibrosis development has not been demonstrated. To evaluate the effect of the PPAR pan agonist MHY2013, a folic acid (FA)-induced in vivo kidney fibrosis model was used. MHY2013 treatment significantly controlled decline in kidney function, tubule dilation, and FA-induced kidney damage. The extent of fibrosis determined using biochemical and histological methods showed that MHY2013 effectively blocked the development of fibrosis. Pro-inflammatory responses, including cytokine and chemokine expression, inflammatory cell infiltration, and NF-κB activation, were all reduced with MHY2013 treatment. To demonstrate the anti-fibrotic and anti-inflammatory mechanisms of MHY2013, in vitro studies were conducted using NRK49F kidney fibroblasts and NRK52E kidney epithelial cells. In the NRK49F kidney fibroblasts, MHY2013 treatment significantly reduced TGF-ß-induced fibroblast activation. The gene and protein expressions of collagen I and α-smooth muscle actin were significantly reduced with MHY2013 treatment. Using PPAR transfection, we found that PPARγ played a major role in blocking fibroblast activation. In addition, MHY2013 significantly reduced LPS-induced NF-κB activation and chemokine expression mainly through PPARß activation. Taken together, our results suggest that administration of the PPAR pan agonist effectively prevented renal fibrosis in both in vitro and in vivo models of kidney fibrosis, implicating the therapeutic potential of PPAR agonists against chronic kidney diseases.

Design and Synthesis of (Z)-2-(Benzylamino)-5-benzylidenethiazol-4(5H)-one Derivatives as Tyrosinase Inhibitors and Their Anti-Melanogenic and Antioxidant Effects.

In this study, (Z)-2-(benzylamino)-5-benzylidenethiazol-4(5H)-one (BABT) derivatives were designed as tyrosinase inhibitors based on the structure of MHY2081, using a simplified approach. Of the 14 BABT derivatives synthesized, two derivatives ((Z)-2-(benzylamino)-5-(3-hydroxy-4-methoxybenzylidene)thiazol-4(5H)-one [7] and (Z)-2-(benzylamino)-5-(2,4-dihydroxybenzylidene)thiazol-4(5H)-one [8]) showed more potent mushroom tyrosinase inhibitory activities than kojic acid, regardless of the substrate used; in particular, compound 8 was 106-fold more potent than kojic acid when l-tyrosine was used as the substrate. Analysis of Lineweaver-Burk plots for 7 and 8 indicated that they were competitive inhibitors, which was confirmed via in silico docking. In experiments using B16F10 cells, 8 exerted a greater ability to inhibit melanin production than kojic acid, and it inhibited cellular tyrosinase activity in a concentration-dependent manner, indicating that the anti-melanogenic effect of 8 is attributable to its ability to inhibit tyrosinase. In addition, 8 exhibited strong antioxidant activity to scavenge 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals and peroxynitrite and inhibited the expression of melanogenesis-associated proteins (tyrosinase and microphthalmia-associated transcription factor). These results suggest that BABT derivative 8 is a promising candidate for the treatment of hyperpigmentation-related diseases, owing to its inhibition of melanogenesis-associated protein expression, direct tyrosinase inhibition, and antioxidant activity.

Development of a pH indicator for monitoring the freshness of minced pork using a cellulose nanofiber.

A cellulose nanofiber (CNF)-based pH-sensitive indicator was developed by mixing CNF with red radish color extract (RRCE) to analyze the freshness of minced pork. Among various mixing conditions of RRCE solutions (0.4-1.6%) and CNF (0.5-1.25%), 0.8% RRCE/1% CNF showing higher mechanical properties, lower response to water, lower leakage of RRCE, and higher sensitivity to ammonia was selected as optimum. Ultraviolet-visible light transmittance and structural properties of the film indicated successful incorporation of RRCE into CNF, with rapid response to changes in pH caused by ammonia solution. The water vapor permeability of the indicator was maintained for 48 h. The fabricated pH-sensitive indicator showed apparent color changes from red color (fresh) to purple color (spoiled) during pork storage at refrigeration temperature. In addition, the deterioration degree was compared by measuring pH, microbial counts, and total volatile base-nitrogen level, confirming the applicability of this CNF-based film as a pH indicator.

Central Auditory Processing Disorder in Patients with Amnestic Mild Cognitive Impairment.

Background: This study was conducted to comprehensively examine the central auditory processing (CAP) abilities of patients with amnestic mild cognitive impairment (aMCI) as well as to compare the results with cognitively normal elderly controls. Methods: A total of 78 participants were screened through pure-tone audiometry and word recognition score in order to exclude peripheral auditory dysfunction. Forty-five people passed screening tests, and 33 people failed. Finally, 25 aMCI (mean age = 71.52 ± 4.8; male : female = 24 : 76) and 20 controls (mean age = 73.45 ± 4.32; male : female = 45 : 55) were enrolled in the study. Seven CAP tests (frequency pattern test, duration pattern test, Gap-In-Noise© test, dichotic digits test, low-pass filtered word test, speech perception in noise test, and binaural fusion test) were conducted only after the two groups passed the screening. A linear mixed model was applied to analyze CAP tests except for the binaural fusion test. For the binaural fusion test, the independent t-test was used to compare the means of test score between two groups. Results: The aMCI group had a decrease in the mean score of the frequency pattern test, duration pattern test, Gaps-In-Noise© test, dichotic digits test, and speech perception in noise test compared with the control group. Conclusion: The aMCI group's CAP abilities were significantly lower than those of the control group. Thus, if the cognitive assessment and hearing evaluation are conducted in combination, the sensitivity of the diagnostic process for aMCI will be increased.

How Does a Face Mask Impact Speech Perception?

Face masks are mandatory during the COVID-19 pandemic, leading to attenuation of sound energy and loss of visual cues which are important for communication. This study explores how a face mask affects speech performance for individuals with and without hearing loss. Four video recordings (a female speaker with and without a face mask and a male speaker with and without a face mask) were used to examine individuals' speech performance. The participants completed a listen-and-repeat task while watching four types of video recordings. Acoustic characteristics of speech signals based on mask type (no mask, surgical, and N95) were also examined. The availability of visual cues was beneficial for speech understanding-both groups showed significant improvements in speech perception when they were able to see the speaker without the mask. However, when the speakers were wearing the mask, no statistical significance was observed between no visual cues and visual cues conditions. Findings of the study demonstrate that provision of visual cues is beneficial for speech perception for individuals with normal hearing and hearing impairment. This study adds value to the importance of the use of communication strategies during the pandemic where visual information is lost due to the face mask.

Influence of the Noise-Canceling Technology on How We Hear Sounds.

PURPOSE: This study explores the influence of the noise-canceling technology in commercial earphones on sound pressure levels and preferred listening levels in terms of hearing protection. MATERIALS AND METHODS: Thirty individuals completed puretone audiometry and real-ear measurements to assess sound pressure levels at the level of the eardrum with and without the activation of the noise-canceling function. The Knowles Electronics Manikin for Acoustic Research was used to investigate the acoustic characteristics of two environmental sounds (bus and café). Two types of earphones (wireless and wired canal type) were utilized in the study. RESULTS: For both bus and café noises, in the low-frequency range, sound pressure levels were significantly decreased for all types of earphones when the noise-canceling function was turned on. The same results were observed for the whole frequency range. In terms of preferred listening levels, the wireless canal type and wired canal type earphones showed significant reduction in volume levels. CONCLUSION: The findings of the study show that for both low- and whole frequency range, the use of noise-canceling function significantly decreases the sound pressure levels of the signal for all styles of earphones, suggesting a potential of the noise-canceling technology in hearing protection.

Robust Detection Model of Vascular Landmarks for Retinal Image Registration: A Two-Stage Convolutional Neural Network.

Registration is useful for image processing in computer vision. It can be applied to retinal images and provide support for ophthalmologists in tracking disease progression and monitoring therapeutic responses. This study proposed a robust detection model of vascular landmarks to improve the performance of retinal image registration. The proposed model consists of a two-stage convolutional neural network, in which one segments the retinal vessels on a pair of images, and the other detects junction points from the vessel segmentation image. Information obtained from the model was utilized for the registration. The keypoints were extracted based on the acquired vascular landmark points, and the orientation features were calculated as descriptors. Then, the reference and sensed images were registered by matching keypoints using a homography matrix and random sample consensus algorithm. The proposed method was evaluated on five databases and seven evaluation metrics to verify both clinical effectiveness and robustness. The results established that the proposed method showed outstanding performance for registration compared with other state-of-the-art methods. In particular, the high and significantly improved registration results were identified on FIRE database with area under the curve (AUC) of 0.988, 0.511, and 0.803 in S, P, and A classes. Furthermore, the proposed method worked well on poor quality and multimodal datasets demonstrating an ability to achieve high AUC above 0.8.

Novel Anatomical Proposal for Botulinum Neurotoxin Injection Targeting Lateral Canthal Rhytids.

Botulinum neurotoxin injections near the lateral canthal rhytids are commonly used in cosmetic settings; however, there is a lack of thorough anatomical knowledge, and an effective way to treat them with accumulating knowledge is needed. The anatomical characteristics concerning the injection of botulinum neurotoxin into the orbicularis oculi muscle were evaluated in this review. Current knowledge on the identification of botulinum neurotoxin injection points from recent anatomical research was assessed. The lateral canthal lines are involved with the orbicularis oculi muscle and nearby anatomical structures, and the injection points can be more precisely defined. The best possible injection sites were provided, and the injection procedure was described. This review proposes evidence for injection sites associated with the surface anatomy of the orbicularis oculi muscles to enhance the effectiveness of easing lateral canthal rhytids.

Percutaneous Bone-Anchored Hearing Implant: Is It Clinically Useful in Korean?

BACKGROUND: The aim of this study is to investigate the clinical effectiveness of Ponto in Korea, a recently released percutaneous bone-anchored hearing implant. METHODS: 16 patients with single-sided deafness (SSD) and mixed or conductive hearing loss who underwent Ponto implantation from December 2018 to September 2020 were enrolled in the study. Puretone audiometry, the Korean version of the Hearing in Noise Test (K-HINT), sound localization test (SLT), and Pupillometry were performed pre- and three months post-operation. Standardized questionnaires, the Hearing Handicap Inventory for the Elderly (HHIE) and Speech, Spatial and Qualities of Hearing Scale (SSQ), were administered. RESULTS: The mean age of subjects was 55.5 (range, 48-67) years. Four males and 12 females participated in the study. The mean puretone average was 73.17 dB hearing level (HL) before surgery and significantly improved to 36.72 dB HL three months after surgery. The mean word recognition score improved from 26.0% to 90.75% after implantation. In the case of K-HINT, there was a significant difference in summation (Z = -2.250, P = 0.024) and head shadow effects (Z = -3.103, P = 0.002). There was no significant difference in root mean square error degree (RMSE) and hemifield identification scores for SLT testing. Pupillometry was performed to measure listening effort and the results revealed that the degree of pupillary dilatation decreased under the condition of quiet, 0 dB signal to noise ratio (SNR) and 3 dB SNR. The total score for HHIE decreased significantly (Z = -3.130, P = 0.002) while the SSQ score increased significantly (Z = -2.216, P = 0.027). CONCLUSIONS: The Ponto bone-anchored hearing system showed significant clinical benefit in Korean patients with conductive and mixed hearing loss and SSD.

Anisotropic Plasmonic Gold Nanorod-Indocyanine Green@Reduced Graphene Oxide-Doxorubicin Nanohybrids for Image-Guided Enhanced Tumor Theranostics.

The unique physicochemical and localized surface plasmon resonance assets of gold nanorods (GNRs) have offered combined cancer treatments with real-time diagnosis by integrating diverse theragnostic modalities into a single nanoplatform. In this work, a unique multifunctional nanohybrid material based on GNRs was designed for in vitro and in vivo tumor imaging along with synergistic and combinatorial therapy of tumor. The hybrid material with size less than 100 nm was achieved by embedding indocyanine green (ICG) on mesoporous silica-coated GNRs with further wrapping of reduced graphene oxide (rGO) and then attached with doxorubicin (DOX) and polyethylene glycol. The nanohybrid unveiled noteworthy stability and competently protected the embedded ICG from further aggregation, photobleaching, and nucleophilic attack by encapsulation of GNRs-ICG with rGO. Such combination of GNRs-ICG with rGO and DOX served as a real-time near-infrared (NIR) contrast imaging agent for cancer diagnosis. The hybrid material exhibits high NIR absorption property along with three destined capabilities, such as, nanozymatic activity, photothermal activity, and an excellent drug carrier for drug delivery. The integrated properties of the nanohybrid were then utilized for the triple mode of combined therapeutics of tumor cells, through synergistic catalytic therapy and chemotherapy with combinatorial photothermal therapy to achieve the maximum cancer killing efficiency. It is assumed that the assimilated multimodal imaging and therapeutic capability in single nanoparticle platform is advantageous for future practical applications in cancer diagnosis, therapy, and molecular imaging.

Factors Influencing Hearing Aid Satisfaction in South Korea.

PURPOSE: The purpose of this study is three-fold: 1) to evaluate factors influencing hearing aid (HA) satisfaction; 2) to provide a profile of HA satisfaction in daily life; and 3) to examine the reasons why people gave up using HAs. MATERIALS AND METHODS: Data for 1148 respondents were statistically analyzed and reported. RESULTS: In the study, age (ß=-0.03, p<0.01), level of education (ß=1.21, p<0.01), HA purchase price (ß=1.50, p<0.01), bilateral amplification (ß=1.23, p<0.01), wearing time (ß=0.28, p<0.01), and HA fitting and fine tuning on a regular basis (ß=1.71, p<0.01) significantly influenced HA satisfaction. In addition, the authors observed that the most satisfactory factors were clarity of sound (53.5%), people's trust in their HA (61.7%), and listening from a quiet environment (72.8%) in the domains of sound quality, HA features, and listening environments, respectively. Finally, with multiple choices being possible, 65% of the 40 respondents who no longer used HAs answered that their HAs ended up in a drawer since the background noise was annoying and distracting. CONCLUSION: This study is significant in that it is a large-scale multi-center research to comprehensively examine the factors influencing HA satisfaction in South Korea. This data will provide helpful information that could lead to the successful rehabilitation of hearing loss with HAs.

Hearing and Speech Perception for People With Hearing Loss Using Personal Sound Amplification Products.

BACKGROUND: Hearing loss (HL) is the most common chronic disease and has been linked to negative health outcomes. Hearing aids (HAs) are regarded as the gold standard for HL management, however, the adoption rate of HAs is relatively low for various reasons. With this background, hearing devices, such as personal sound amplification products (PSAPs) received significant attention as an alternative to conventional HAs. This study aimed to evaluate the clinical efficacy of PSAPs in patients with mild to moderately severe HL. METHODS: Nineteen patients with mild hearing loss (MHL), 23 with moderate hearing loss (MDHL), and 15 with moderately severe hearing loss (MSHL) participated in the study. Electroacoustic analysis, simulated real-ear measurements (REMs), and three clinical evaluations were implemented. RESULTS: All devices satisfied the electroacoustic tolerances. All devices provided sufficient gain for MHL and MDHL audiograms. However, in MSHL audiogram, the gains of PSAPs were insufficient, especially for high frequencies. In terms of clinical evaluations, sound-field audiometry showed significant improvements between aided and unaided thresholds in all groups for all devices (P < 0.001). Significant improvements of word recognition scores were only shown for HAs between aided and unaided conditions. The Korean version of the Hearing In Noise Test did not show any consistent findings for all devices and groups. CONCLUSION: Certain PSAPs are beneficial for improving hearing and speech perception in patients with HL. Well-chosen PSAPs could be an alternative hearing rehabilitation option for these patients.

Real-World Effectiveness of Wearable Augmented Reality Device for Patients With Hearing Loss: Prospective Study.

BACKGROUND: Hearing loss limits communication and social activity, and hearing aids (HAs) are an efficient rehabilitative option for improving oral communication and speech comprehension, as well as the psychosocial comfort of people with hearing loss. To overcome this problem, over-the-counter amplification devices including personal sound amplification products and wearable augmented reality devices (WARDs) have been introduced. OBJECTIVE: This study aimed to evaluate the clinical effectiveness of WARDs for patients with mild to moderate hearing loss. METHODS: A total of 40 patients (18 men and 22 women) with mild to moderate hearing loss were enrolled prospectively in this study. All participants were instructed to wear a WARD, Galaxy Buds Pro (Samsung Electronics), at least 4 hours a day for 2 weeks, for amplifying ambient sounds. Questionnaires including the Korean version of the abbreviated profile of hearing aid benefit (K-APHAB) and the Korean adaptation of the international outcome inventory for hearing aids (K-IOI-HA) were used to assess personal satisfaction in all participants. Audiologic tests, including sound field audiometry, sound field word recognition score (WRS), and the Korean version of hearing in noise test (K-HINT), were administered to 14 of 40 patients. The tests were performed under two conditions: unaided and aided with WARDs. RESULTS: The mean age of the participants was 55.4 (SD 10.7) years. After 2 weeks of the field trial, participants demonstrated a benefit of WARDs on the K-APHAB. Scores of 3 subscales of ease of communication, reverberation, and background noise were improved significantly (P<.001). However, scores regarding aversiveness were worse under the aided condition (P<.001). K-IOI-HA findings indicated high user satisfaction after the 2-week field trial. On audiologic evaluation, the K-HINT did not show significant differences between unaided and aided conditions (P=.97). However, the hearing threshold on sound field audiometry (P=.001) and the WRS (P=.002) showed significant improvements under the aided condition. CONCLUSIONS: WARDs can be beneficial for patients with mild to moderate hearing loss as a cost-effective alternative to conventional hearing aids.