Worldwide Prevalence of Hearing Loss Among Smartphone Users: Cross-Sectional Study Using a Mobile-Based App

Abstract

Background In addition to the aging process, risk factors for hearing loss in adults include, among others, exposure to noise, use of ototoxic drugs, genetics, and limited access to medical care. Differences in exposure to these factors are bound to be reflected in the prevalence of hearing loss. Assessment of hearing loss can easily be carried out on a large scale and at low cost using mobile apps. Objective This study aimed to conduct a worldwide assessment of the differences in hearing loss prevalence between countries in a group of mobile device users. Methods Hearing tests were conducted using the open-access Android-based mobile app Hearing Test. The app is available free of charge in the Google Play store, provided that consent to the use of the results for scientific purposes is given. This study included hearing tests carried out on device models supported by the app with bundled headphones in the set. Calibration factors for supported models were determined using the biological method. The tests consisted of self-determining the quietest audible tone in the frequency range from 250 Hz to 8 kHz by adjusting its intensity using the buttons. The ambient noise level was optionally monitored using a built-in microphone. Following the test, the user could compare his hearing threshold against age norms by providing his or her age. The user's location was identified based on the phone’s IP address. Results From November 23, 2016 to November 22, 2019, 733,716 hearing tests were conducted on 236,716 mobile devices across 212 countries. After rejecting the tests that were incomplete, performed with disconnected headphones, not meeting the time criterion, repeated by the same user, or carried out regularly on one device, 116,733 of 733,716 tests (15.9%) were qualified for further analysis. The prevalence of hearing loss, defined as the average threshold at frequencies 0.5 kHz, 1 kHz, 2 kHz, and 4 kHz above 25 dB HL in the better ear, was calculated at 15.6% (95% CI 15.4-15.8). Statistically significant differences were found between countries (P<.001), with the highest prevalences for Bangladesh, Pakistan, and India (>28%) and the lowest prevalences for Taiwan, Finland, and South Korea (<11%). Conclusions Hearing thresholds measured by means of mobile devices were congruent with the literature data on worldwide hearing loss prevalence. Uniform recruitment criteria simplify the comparison of the hearing loss prevalence across countries. Hearing testing on mobile devices may be a valid tool in epidemiological studies carried out on a large scale.

Diagnostic Accuracy of Smartphone-Based Audiometry for Hearing Loss Detection: Meta-analysis

“…Future studies with homogenous gold standards and uniform protocols for smartphone-based hearing tests are needed. Third, ambient noise monitoring is a key factor influencing the accuracy of audiometry [ 75 ]. Although most of the included studies did monitor noise, no data on the accuracy without ambient noise monitoring were provided.…”

“…Sixth, of the 25 included studies, most did not describe the calibration method, whereas 9 (36%) used reference equivalent threshold sound pressure levels. A previous study revealed that the differences in hearing thresholds among the device models were significant, which might directly result from the biological calibration method used to determine the reference sound level [ 75 ]. Calibration information was lacking, possibly because of the intrinsic lack of a calibration function in the app.…”

Optimization of the Speech Test Material in a Group of Hearing Impaired Subjects: A Feasibility Study for Multilingual Digit Triplet Test Development

“…In other words, when the percentage of normal-hearing subjects in a study population is known, optimization can be performed on up to the same percentage of the best results, as they are bound to be within the norms. The percentage itself, can be easily estimated from, e.g., preliminary measurements or literature data [ 8 ] without having to check each subject for a normal hearing threshold.…”

“…Communication difficulties, low self-esteem, and isolation lead to social exclusion and depression [ 1 , 2 , 3 ]. Currently, worldwide hearing loss prevalence is estimated between 4.0% and 18.1% [ 1 , 4 , 5 , 6 , 7 , 8 ]. Despite significant variation in the estimated values resulting primarily from the adopted methodology, the prevalence increases globally due to the aging of the worldwide population and the strong positive correlation between hearing impairment and age [ 4 , 5 , 9 ].…”

“…Mobile-based hearing tests can be carried out at low cost and on a large scale [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. They are applied as screening tests, especially in underserved areas, in preliminary evaluation of audiological patients, in self-monitoring of hearing or even in epidemiological studies [ 8 , 16 , 17 , 19 , 20 , 21 , 22 ]. Such applications increase awareness of hearing loss and motivate to take individual and systemic preventive measures [ 5 , 23 ].…”