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Cho, Kim, Choi, Baek, Seol, Lim, Park, and Moon: Factors Influencing Hearing Aid Adoption in Patients With Hearing Loss in Korea
Original Article
Medicine General & Policy

Journal of Korean Medical Science 2021; 37(2): e11.

Published online: 14 December 2021

DOI: https://doi.org/10.3346/jkms.2022.37.e11

Factors Influencing Hearing Aid Adoption in Patients With Hearing Loss in Korea

Young Sang Cho1, 2, *, Ga-Young Kim1, *, Jae Hyuk Choi2, Sin Sung Baek3, Hye Yoon Seol1, 4, Jihyun Lim5, Jin Gyun Park3, Il Joon Moon1, 2

1Hearing Research Laboratory, Samsung Medical Center, Seoul, Korea.

2Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.

3Demant Korea Co., Ltd., Seoul, Korea.

4Medical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Korea.

5Center for Clinical Epidemiology, Samsung Medical Center, Seoul, Korea.

Address for Correspondence: Il Joon Moon, MD, PhD. Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 06351, Korea. moonij@skku.edu

Address for Correspondence: Jin Gyun Park, MA. Demant Korea Co., Ltd., 3, 4, 5, 6, 7 Floor, Seoyoung Building, 99, Seosomun-ro, Jung-gu, Seoul 04516, Korea. jinp@demant.com

Equal contributor:

*These authors contributed equally to this work as co-first author.

Received 12 August 2021       Accepted 19 November 2021

© 2022 The Korean Academy of Medical Sciences.

The Korean Academy of Medical Sciences

https://creativecommons.org/licenses/by-nc/4.0/
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background

The purpose of this study was two-fold: 1) to identify differences in the characteristics of adopters and non-adopters of hearing aids (HAs); and 2) to investigate factors influencing the purchase of HA.

Methods

This study was conducted among 1,464 subjects (818 male and 646 female) with hearing loss. A national face-to-face survey was performed from August 2019 to October 2020 by otologists or HA experts. The questionnaire consisted of three domains: demographic, audiological, and HA-related domains. Multivariate logistic regression analysis was performed after adjusting for degree of hearing loss.

Results

The mean age of the participants was 70.4 ± 12.2 years. Of the 1,464 respondents, 1,190 (81.3%) had already purchased HA. We identified educational level, household income, hearing loss period, place of HA purchase, and government HA assistance program status as factors influencing HA adoption. Among these factors, third party reimbursement was the most important factor affecting HA purchase intent. The main reasons for not adopting HA were feeling that their hearing was adequate, inability to afford HA, and perceptions that HA are uncomfortable.

Conclusion

Various factors are involved in the purchase of HA, but disabled registration status and third party reimbursement were identified as the most critical factors. In the future, the government should take a more active role in increasing the distribution of HA to patients with hearing loss.

Graphical Abstract

jkms-37-e11-abf001.jpg

Keywords: Hearing Loss, Hearing Aids, Surveys and Questionnaires, Health Services for the Aged

INTRODUCTION

According to a recent World Health Organization (WHO) report, an estimated 1.5 billion people worldwide now have hearing loss, and more than 5% (430 million) of the world’s population require hearing rehabilitation due to severe hearing loss. As the population ages, nearly 2.5 billion people are expected to experience some degree of hearing loss by 2050, of which at least 700 million will need hearing rehabilitation.1
South Korea’s population is rapidly aging at an unprecedented rate.2 The aging of the Korean population is progressing much faster than Japan, a representative aged country, and Korea will become a super-aged society (20% of the population in the 65 or over) after 2025.3 Hearing impairment has a significant impact on quality of life and may lead to cognitive decline.45 Therefore, active hearing rehabilitation is essential. However, the adoption rate of hearing aids (HAs) in Korea is relatively low compared to other countries. According to a previous study, the prevalences of HA acquisition and regular use were 17.4% and 12.6%, respectively.6 The main reasons for the low adoption rate of HA in Korea were outlined as follows: 1) inconvenient to wear; 2) high purchase price and maintenance cost; and 3) stigma against HA wearers.7 However, this study was conducted ten years ago and included only 317 respondents. As the adoption rate of HA has grown steadily in recent years, a further comprehensive investigation including current trends is necessary.
A large-scale survey of HA users has periodically been conducted by MarkeTrak in the United States since 2004 and published by the Better Hearing Institute (BHI) on behalf of the hearing care industry.8 In Europe, the European Hearing Instrument Manufacturers Association (EHIMA) began the EuroTrak study, an extensive study of hearing loss and HA, in 2009.9 These detailed and continuous nationwide surveys are helpful to monitor patients seeking HA and can be used as primary data for marketing HAs. These data help manufacturers seeking to increase the level of HA adoption by creating and providing products that are more suitable for people in need of HAs. Adoption of HA is associated with cognitive improvement and may reduce the social costs associated with hearing loss, which are projected to become enormous in the future. Unfortunately, a systematic survey of HA adoption has never been implemented in Korea. We constructed a survey and analyzed our data to describe the current status of the Korean HA market based on recent survey research, similar to MarkeTrak and EuroTrak. Our first goal was to investigate factors that influence the adoption of HA.

METHODS

Participants

We conducted a large-scale prospective survey of patients who visited hospitals or HA centers due to hearing loss. A total of 1,555 individuals were surveyed across South Korea. We excluded 62 pediatric patients (under 18 years of age), 17 respondents who did not answer whether they intended to purchase HA, and 12 respondents who answered that they had purchased HA even though their hearing was normal. Finally, we analyzed data for 1,464 respondents. The flow chart of participants is shown in Fig. 1. The mean age was 70.4 ± 12.2 years, and there were 818 males and 646 females.
Fig. 1

Flow chart of participants.

HA = hearing aid.
jkms-37-e11-g001

Survey questionnaire

Survey items relating to each of the variables of interest in this study were selected from those included in a large-scale survey based on theoretical and methodological considerations drawn from prior research. The dependent variable was a binary variable indicating whether to purchase HA. Independent variables were classified into three domains: demographic, audiological, and HA-related. The demographic domain included age, level of education, household income, and occupation. The audiological domain encompassed the total score of the Korean version of the Hearing Handicap Inventory for the Elderly (K-HHIE), hearing loss duration, disability registration status, and tinnitus. The HA-related domain consisted of the first HA consultation institution, HA recommendation during consultation, and obtaining HA-related information.

Data collection

The face-to-face survey was conducted by otologists or HA experts on a national basis. The data were collected at 10 tertiary hospitals, 7 general hospitals, 11 clinics, 22 HA centers, 3 medical equipment distributors, 1 community welfare center, and 1 other. The survey was conducted in multiple regions at 11 locations in Seoul, 13 locations in Gyeonggi-do, 5 locations in Incheon, 3 locations in Busan, 3 locations in Gangwon-do, 2 locations in Gwangju, 1 location in Gyeongsangbuk-do, 2 locations in Daejoen, 2 locations in Jeollabuk-do, 2 locations in Chungcheongbuk-do, and 1 location in Jeju. The data were collected by the Big Data center of Demant Korea and the Hearing Research Laboratory of SMC.

Statistical analysis

Data were analyzed using SAS ver. 9.4 (SAS Institute, Cary, NC, USA) and STATA ver. 14 (StataCorp, College Station, TX, USA) at the Clinical Epidemiology Center of SMC. The specific method of analysis is as follows:

  • 1) An independent t-test or χ2 test was performed to identify the characteristics of HA owners and non-adopters.

  • 2) Factors influencing whether to purchase HA were confirmed through multivariate logistic regression after adjusting for degree of hearing loss. Variables with P values < 0.15 in the independent t-test or χ2 test were included as independent variables.

Ethics statement

The present study protocol was reviewed and approved by the Institutional Review Board of Samsung Medical Center (approval No. 2019-06-116). Informed consent was submitted by all subjects when they were enrolled.

RESULTS

Differences in characteristics between HA adopters and non-adopters

Among the 1,464 respondents, 1,190 (81.3%) purchased HA. Among the demographic characteristics, there were significant differences in age (P = 0.002), level of education (P = 0.002), household income (P = 0.005), and occupation (P = 0.003) between the HA purchase group and HA non-purchase group. Regarding audiological features, there were differences between HA adopters and non-adopters in all of the items investigated. There were significant differences in K-HHIE total score (P = 0.005), hearing loss duration (P = 0.003), disabled registration status (P = 0.002), and tinnitus (P = 0.005) between groups. In terms of HA-related traits, there were significant differences in first HA consultation institution (P = 0.004) and HA recommendation during consultation (P = 0.007) (Table 1).
Table 1

Characteristics of HA adopters and non-adopters (N = 1,464)

jkms-37-e11-i001
Variables HA adoption P value
No (n = 274) Yes (n = 1,190)
Domain 1: Demographic
Age 65.6 (15.5) 71.5 (13.6) 0.002**
Sex 0.341
Male 146 (53.3) 672 (56.5)
Female 128 (46.7) 518 (43.5)
Degree of hearing lossa 0.005**
Normal 13 (4.7) 0 (0.0)
Mild 75 (27.4) 85 (7.1)
Moderate 100 (36.5) 516 (43.4)
Severe 19 (6.9) 296 (24.9)
Profound 6 (2.2) 115 (9.7)
Unknown 61 (22.3) 178 (15.0)
Level of education 0.002**
Middle school graduate or below 48 (17.5) 376 (31.6)
High school graduate 109 (39.8) 337 (28.3)
University graduate 90 (32.9) 261 (21.9)
No response 27 (9.9) 216 (18.2)
Household income (mon) 0.005**
$1,000 or less 42 (15.3) 362 (30.4)
Less than $1,000 to $5,000 109 (39.8) 481 (40.4)
Less than $5,000 to $10,000 27 (9.9) 104 (8.7)
$10,000 or more 16 (5.8) 18 (1.5)
No response 80 (29.2) 225 (18.9)
Job 0.003**
Office job 54 (19.7) 148 (12.4)
Blue-collar job 102 (37.2) 339 (28.5)
Unemployment 91 (33.2) 442 (37.1)
Etc. 27 (9.9) 261 (21.9)
Domain 2: Audiological
K-HHIE total score (n = 1,398) 14.0 (9.5) 19.4 (9.1) 0.005**
Hearing loss duration (mon) (n = 1,398) 40 (68.1) 138.3 (166.3) 0.003**
Disabled registration status 0.002**
No 222 (81.0) 662 (55.6)
Yes 4 (1.5) 492 (41.3)
No response 48 (17.5) 36 (3.0)
Tinnitus 0.005**
No 148 (54.0) 735 (61.8)
Yes 83 (30.3) 405 (34.0)
No response 43 (15.7) 50 (4.2)
Domain 3: HAs-related
First HAs consultation institution 0.004**
Hospital 46 (16.8) 434 (36.5)
HA center 47 (17.2) 728 (61.2)
Etc. 181 (66.1) 28 (2.4)
HAs recommendation during a consultation 0.007**
No 79 (28.8) 139 (11.7)
Yes 120 (43.8) 996 (83.7)
No response 75 (27.4) 55 (4.6)
Values are presented as number (%).
HA = hearing aid, K-HHIE = Korean version of the Hearing Handicap Inventory for the Elderly.
aIt is the degree of subjective hearing loss, and it is defined as the severe one among the degree of hearing loss in both ears. If there is no degree of hearing loss in both ears, it is defined as unknown.
**P < 0.01.

Factors influencing HA purchase

Multivariate logistic regression analysis was performed using variables showing significance in the univariate analysis (P < 0.15). Consequently, level of education, household income, hearing loss duration, disability registration, and first HA consultation institution were significant factors for HA adoption. In terms of level of education, individuals who were middle school graduates or below were 1.86 times (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.03–3.37), and university graduates were two times (OR, 2.00; 95% CI, 1.11–3.60) more likely to purchase HA compared to high school graduates. In terms of household income, respondents who earned less than $1,000 to $5,000 were 1.12 times (OR, 1.12; 95% CI, 0.55–2.27), less than $5,000 to $10,000 were 1.18 times (OR, 1.18; 95% CI, 0.40–3.46), and $10,000 or more were 1.69 times (OR, 1.69; 95% CI, 0.30–9.71) more likely to purchase HA compared to those earning $1,000 or less. Related to hearing loss duration, tendency to purchase HA became 1.01 times (OR, 1.01; 95% CI,1.01–1.02) higher every month for the duration of hearing loss increased. Regarding government assistance status, those who received a 3rd party reimbursement were 19.44 times (OR, 19.44; 95% CI, 5.99–63.07) more likely to purchase HA compared to those who received no reimbursement. Regarding the first HA consultation institution, respondents who received consultations at a HA center were 2.1 times (OR, 2.10; 95% CI, 1.27–3.49) more likely to purchase HA than those who received consultations at hospitals (Table 2).
Table 2

Logistic regression models for HA adoption in patients with hearing loss

jkms-37-e11-i002
Variables Multivariate analysis P value
Domain 1: Demographic
Age 1.01 (0.99–1.03) 0.352
Sex 0.911
Male Reference
Female 1.03 (0.65–1.62)
Level of education 0.005**
Middle school graduate or below 1.86 (1.03–3.37)
High school graduate Reference
University graduate 2.00 (1.11–3.60)
Household income (mon) 0.005**
$1,000 or less Reference
Less than $1,000 to $5,000 1.12 (0.55–2.27)
Less than $5,000 to $10,000 1.18 (0.40–3.46)
$10,000 or more 1.69 (0.30–9.71)
No response 0.13 (0.06–0.31)
Job 0.054
Office job Reference
Blue-collar job 0.63 (0.30–1.34)
Unemployment 0.61 (0.27–1.39)
Etc. 3.69 (0.84–16.24)
Domain 2: Audiological
K-HHIE total score (n = 1,398) 1.00 (0.97–1.03) 0.852
Hearing loss duration (mon) (n = 1,398) 1.01 (1.01–1.02) 0.003**
Disabled registration status
No Reference
Yes 19.44 (5.99–63.07)
Tinnitus 0.002**
No 1.26 (0.78–2.02)
Yes Reference
Domain 3: HAs-related
First HAs consultation institution 0.005**
Hospital Reference
HAs center 2.10 (1.27–3.49)
Etc. 0.01 (0.0–0.03)
HAs recommendation during a consultation 0.731
No Reference
Yes 1.19 (0.59–2.38)
Values are presented as odds ratio (95% confidential interval).
HA = hearing aid, K-HHIE = Korean version of the Hearing Handicap Inventory for the Elderly.
**P < 0.01.

Descriptive analysis of reasons for non-adoption of HA, factors affecting purchasing decisions, and intention to purchase HA

Two hundred and sixty-seven people who did not purchase HA elucidated reasons for non-adoption of HA, factors affecting purchasing decisions, and intention to purchase HA in the future. The top three reasons cited were: can hear well enough (52.9%), cannot afford (27.7%), and negative perception (23.4%) (Fig. 2). The three most common factors affecting the purchasing decision were progression of hearing loss (75.9%), cost of HA (29.2%), and suggestion of health care professionals (23.8%) (Fig. 3). Furthermore, 86% of respondents said they are willing to purchase HA in the future.
Fig. 2

Reasons for non-adoption of HAs (n = 267; multiple choice).

HA = hearing aid, HCP = hearing care professionals.
jkms-37-e11-g002
Fig. 3

Factors affecting purchasing decisions (n = 267; multiple choice).

HA = hearing aid, HCP = hearing care professionals.
jkms-37-e11-g003

DISCUSSION

This is the first large-scale, systematic, comprehensive study of HA adoption in Korea. In the context of a rapidly increasing elderly population, we comprehensively analyzed factors influencing HA purchase. These factors were education level, household income, hearing loss duration, disabled registration status, and first HA consultation institution.
The HA adoption rate was 1.86 times higher among individuals who were middle school graduates or below (low-educated) and two times higher among university graduates (high-educated) compared to high school graduates. This is because low-educated respondents have a high probability of belonging to lower household income strata, and therefore receive 100% HA subsidies. High-educated respondents might be more likely to purchase HA due to greater awareness of the importance of hearing rehabilitation and higher household income.
Financial constraints are considered significant barriers to HA adoption. The MarkeTrak10 survey indicated that household income impacts the decision to purchase HA.10 In a 2007 survey, about 76% of respondents answered that financial issues were a barrier to HA adoption.11 In addition, 64% of the responders reported that they could not afford HA, and nearly half (49%) indicated financial problems were straightforward reasons for non-adoption of HA. The drastic improvement in the economy affected about 1 in 5 people (18%) with moderate-severe hearing loss in the U.S. when deciding to purchase HA.12 Our findings were in line with previous surveys indicating that the higher the household income, the greater the availability of HA. Furthermore, 27% of the non-adopters responded that they do not use HA because they cannot afford the cost. Although there were no significant differences in the HA adoption rates according to workplace in this survey, office workers were more likely to adopt HA than blue-collar workers or unemployed respondents. This also indirectly explains the impact of financial factors on HA purchases. According to EuroTrak UK 2018 data, people with HA recognize that HA increase the chances of hearing impaired individuals to be promoted, to obtain good jobs, and to attain higher salaries. Therefore, it is necessary to analyze the HA adoption rate of office workers in the future by dividing the sample into specific occupational groups.
In Korea, until 2015, registered persons with hearing disabilities were eligible for only about $300 per ear under Korean National Health Insurance reimbursement rules. However, since government subsidy rates have more than tripled from $300 to $1,150 in November 2015, the HA adoption rate has rapidly increased. These policies are intended to relieve the financial burden of hearing loss and offer HAs of good quality at reasonable prices. In this study, the proportion of respondents with third party reimbursement was 19.44 times higher than those without reimbursement. This results in a much greater effect than the previously mentioned impact of household income on HA purchases. Therefore, third party reimbursement is one of the most critical factors for HA adoption. These results agree with those of the MarkeTrak10 survey, showing that the rate of the likelihood of HA adoption rises with increased rates of insurance coverage.10
The decision to acquire HAs is also dependent on hearing loss duration. According to the MarkeTrak10 survey, HA adopters reported longer durations of hearing loss (mean duration of hearing loss = 14.6 years) than HA non-adopters (mean = 10.5 years).10 The survey found that HA adopters tended to be older and to have more significant hearing loss. In the present survey, HA adopters (mean age = 71.5 years) were significantly older than HA non-adopters (mean age = 65.6 years) (P < 0.01). Age-related hearing loss is characterized by gradual, progressive sensorineural hearing loss leading to impaired communication. Therefore, the elderly are the main users of HAs. However, age alone was not a predictor of HA purchase.
We found that the HA adoption rate was approximately twice as high when receiving HA counseling at a HA center rather than a hospital. The reason for this is that many hearing loss patients who have visited hospitals expect other treatments, such as surgery or medication, in addition to HA, and may undergo hearing rehabilitation through other methods. However, patients who visit HA center may visit with the intention to purchase HA. In the MarkeTrak8 survey, the frequency of purchasing HA after being referred by an audiologist rather than an ear, nose, and throat doctor was slightly higher.12
A recent study of HA adoption among Americans reported that married status, white race, high socioeconomic status, poor hearing, and high HHIE scores increase the adoption rate of HA.13 In our study, we found that the higher the HHIE score, the higher the probability of adopting HA, but there were no significant differences according to degree of hearing loss. This suggests that if the degree of hearing loss is similar, the price or support policies surrounding HA may be more important than the discomfort caused by hearing loss itself.
We further studied the reasons for non-adoption of HA, factors affecting purchasing decisions, and intention to purchase HA. The greater reason for non-adoption of HA and factors affecting the purchasing decision were directly related to hearing. In general, older people tend to underestimate their hearing loss.14 In the Korea National Health and Nutrition Examination Survey conducted several years ago, 13.1% of subjects underestimated their hearing loss compared to their actual hearing.15 This discrepancy is also an important barrier to purchasing HA. However, hearing loss can lead to other disorders such as depression, falling and cognitive impairment. Therefore, it is necessary to regularly conduct hearing evaluations for the elderly and to rehabilitate hearing with HA in a timely and appropriate manner to prevent or delay further deterioration. In addition, barriers to the adoption of HA included negative perceptions and cost of HA. In this case, other types of hearing devices, such as personal sound amplification products, may be options for patients with mild-to-moderate hearing loss.1617
This study has limitations. First, the HA adoption rate reported in this study is much higher than in previous research. One possible explanation may be sampling bias. The data were mainly collected at hospital outpatient clinics or HA centers. However, our main purpose was to investigate factors influencing HA adoption, and it is necessary to focus on these results. Second, this study was a retrospective analysis of existing clinical data. In particular, the degree of hearing loss of the subjects could not be evaluated objectively like the pure tone hearing average or speech discrimination score. Similarly, we could not add more variables that could be related to HA adoption, including hearing outcomes. Further prospective research is required to explore such variables further.
In conclusion, education level, duration of hearing loss, household income, and place of purchase were important factors associated with intention to purchase HA, with third party reimbursement identified as the most prominent factor. These findings suggest that the government needs to play a more active role in increasing the distribution of HA to patients with hearing loss in South Korea in the future.

Notes

Disclosure: The authors have no potential conflicts of interest to disclose.

Author Contributions:

  • Conceptualization: Cho YS, Kim GY, Baek SS, Seol HY, Park JG, Moon IJ.

  • Data curation: Lim J, Choi JH.

  • Formal analysis: Cho YS, Kim GY, Lim J.

  • Investigation: Baek SS.

  • Methodology: Cho YS, Kim GY, Baek SS, Park JG, Moon IJ.

  • Project administration: Baek SS, Park JG.

  • Supervision: Park JG, Moon IJ.

  • Writing - original draft: Cho YS, Kim GY, Writing - review & editing.

References

1. World Health Organization. Deafness and hearing loss. Updated 2021. Accessed April 16, 2021. https://www.who.int/news-room/fact-sheets/detail/deafness-and-hearing-loss .
2. Hyun KR, Kang S, Lee S. Population aging and healthcare expenditure in Korea. Health Econ. 2016; 25(10):1239–1251. PMID: 26085120.
crossref
3. United Nations. World population prospects 2019. Updated 2019. Accessed April 3, 2021. https://population.un.org/wpp/Download/Standard/Population/ .
4. Loughrey DG, Kelly ME, Kelley GA, Brennan S, Lawlor BA. Association of age-related hearing loss with cognitive function, cognitive impairment, and dementia: a systematic review and meta-analysis. JAMA Otolaryngol Head Neck Surg. 2018; 144(2):115–126. PMID: 29222544.
5. Song JJ, Ku EJ, Kim S, Kim E, Choi YS, Jung HJ. Increased risk of psychopathological abnormalities in subjects with unilateral hearing loss: a cross-sectional study. Clin Exp Otorhinolaryngol. 2021; 14(1):82–87. PMID: 32734740.
crossref
6. Moon IJ, Baek SY, Cho YS. Hearing aid use and associated factors in South Korea. Medicine (Baltimore). 2015; 94(42):e1580. PMID: 26496259.
crossref
7. National Evidence-based Healthcare Collaborating Agency (KR). Analysis of hearing aid benefit and barriers in hearing aid acquisition in Korea (NECA 2010-008). Updated 2021. Accessed April 16, 2021. https://policy.nl.go.kr/search/searchDetail.do?rec_key=SH2_PLC20170213095 .
8. Powers TA, Rogin CM. MarkeTrak 10: Hearing aids in an era of disruption and DTC/OTC devices. Hear Rev. 2019; 26(8):12–20.
9. Hougaard S. EuroTrak. Updated 2011. Accessed April 16, 2021. https://www.hearingreview.com/hearing-products/amplification/assistive-devices/eurotrak .
10. Jorgensen L, Novak M. Factors influencing hearing aid adoption. Semin Hear. 2020; 41(1):6–20. PMID: 32047345.
crossref
11. Kochkin S. MarkeTrak VII: Obstacles to adult non-user adoption of hearing aids. Hear J. 2007; 60(4):24–51.
12. Kochkin S. MarkeTrak VIII: Consumer satisfaction with hearing aids is slowly increasing. Hear J. 2010; 63(1):19–20.
crossref
13. Simpson AN, Matthews LJ, Cassarly C, Dubno JR. Time from hearing aid candidacy to hearing aid adoption: a longitudinal cohort study. Ear Hear. 2019; 40(3):468–476. PMID: 30085938.
crossref
14. Ogawa T, Uchida Y, Nishita Y, Tange C, Sugiura S, Ueda H, et al. Hearing-impaired elderly people have smaller social networks: a population-based aging study. Arch Gerontol Geriatr. 2019; 83:75–80. PMID: 30965190.
crossref
15. Choi JE, Moon IJ, Baek SY, Kim SW, Cho YS. Discrepancies between self-reported hearing difficulty and hearing loss diagnosed by audiometry: prevalence and associated factors in a national survey. BMJ Open. 2019; 9(4):e022440.
crossref
16. Kim GY, Kim JS, Jo M, Seol HY, Cho YS, Moon IJ. Feasibility of personal sound amplification products in patients with moderate hearing loss: a pilot study. Clin Exp Otorhinolaryngol. Forthcoming. 2021; DOI: 10.21053/ceo.2020.02313.
crossref
17. Seol HY, Kim GY, Kang S, Jo M, Han UG, Cho YS, et al. Clinical comparison of a hearing aid, a personal sound amplification product, and a wearable augmented reality device. Clin Exp Otorhinolaryngol. 2021; 14(3):359–361. PMID: 33735561.
crossref
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