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Pure-tone screening (PTS) is considered as the gold standard for hearing screening programs in school-age children. Mobile devices, such as mobile phones, have the potential for audiometric testing.
This study aimed to demonstrate a new approach to rapidly screen hearing status and provide stratified test values, using a smartphone-based hearing screening app, for each screened ear of school-age children.
This was a prospective cohort study design. The proposed smartphone-based screening method and a standard sound-treated booth with PTS were used to assess 85 school-age children (170 ears). Sound-treated PTS involved applying 4 test tones to each tested ear: 500 Hz at 25 dB and 1000 Hz, 2000 Hz, and 4000 Hz at 20 dB. The results were classified as
A total of 85 subjects (170 ears), including 38 males and 47 females, aged between 11 and 12 years with a mean (SD) of 11 (0.5) years, participated in the trial. Both screening methods produced comparable
The results of the proposed smartphone-based self-hearing test demonstrated high concordance with conventional PTS in a sound-treated booth. Our results suggested the potential use of the proposed smartphone-based hearing screening in a school-age population.
Worldwide, more than 466 million (over 5%) people, including 34 million children, are estimated to have a hearing impairment. Hearing impairment is difficult to monitor because of the limited availability of testing equipment and trained specialists in many developing countries [
Pure-tone screening (PTS) is considered as the gold standard for hearing screening programs for school-age children [
The Hearing Scale Test (HST) is a novel hearing screening method derived from the consecutive hearing screening procedures for approaching the current hearing status of each screened ear of children [
Automated audiometry devices have demonstrated that comparable hearing threshold values, compared with those obtained by automated audiometry, such as computer-assisted audiometry [
In this study, we developed an iOS-based smartphone hearing test app
Stimulus levels in dB hearing level for tested frequencies in the proposed Hearing Scale Test.
Stimulation level | Hearing Scale Test | ||||||||||
Normal (pure-tone audiometry ≤25 dB) | Possible hearing impairment (pure-tone audiometry >25 dB) | ||||||||||
Sa1 | S2 | S3 | S4 | S5 | S6 | S7 | S8 | S9 | S10 | ||
1000 Hz, 2000 Hz, and 4000 Hz | 0 | 5 | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | |
500 Hz | 5 | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | 50 |
aS: stratified hearing scale.
This prospective cohort study was conducted at an elementary school in Taipei, Taiwan. We recruited children from grades 5 and 6, aged between 11 and 12 years. A total of 85 children (38 boys and 47 girls) were enrolled, with 170 ears tested. The trial was approved by the Institutional Review Board of Taipei Veterans General Hospital (2017-10-003CC). Written informed consent was collected by the teachers from the parents, before the scheduled date of the hearing screening tests. After instruction by the researchers, each child, in a random order, underwent smartphone-based and booth-based hearing screening consecutively. The smartphone-based hearing screening procedures were performed in a quiet room in the school. Before the hearing screening, the students were taught how to wear the headphones and push a button when hearing the tone. The air conditioner was turned off during the measurements to reduce ambient noise, the level of which was monitored every 30 min by a sound level meter to ensure an ambient noise level of less than 50 dB at test frequencies of 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz.
The audiologist manually controlled a GrasonStadler GSI 18 screening audiometer that was used with a Telephonics TDH-39 supraaural earphones previously calibrated according to International Organization for Standardization (ISO) 389-1. A
The iOS-based automated
Calibration of iOS-based devices with Apple EarPod RETSPLs was described in detail in a previous paper [
For hearing screening, the presence or absence of hearing loss (PTA>25 dB) in each ear was determined by sound-treated booth audiometry. The results from the Ear Scale app were compared with the threshold obtained from sound-treated booth PTA measurement. These data were entered into 2×2 tables to calculate the sensitivity, specificity, positive predictive value, and negative predictive value. The hearing scale obtained from the Ear Scale app and the corresponding mean pure-tone threshold obtained from the sound-treated booth are shown by a box plot (
Screenshot of the Ear Scale app includes instructions for the testers and the hearing test process.
The computerized smartphone-based hearing screening flow diagram. S: stratified hearing scale.
Box plots of the hearing results of right ears and left ears obtained from the Ear Scale app in relation to those obtained from pure-tone screening. The box includes the median (heavy line) and represents the first and third quartiles, whereas the vertical bar indicates the SD. Blue lines represent best-fit linear regressions of the means of the boxes, whereas the gray areas around the line represent the 95% CI of the model (P<.05, differences were found between groups). S: stratified hearing scale.
Of the 170 ears tested by sound-treated booth PTA, 98.8% (168/170) and 1.2% (2/170) were assigned
Participants’ demographics and hearing impairment candidacy (as graded by the pure-tone screening and Hearing Scale Test).
Variables | Statistics | |
Participants, n | 85 | |
Age (years), mean (SD) | 11 (0.5) | |
Male | 38 | |
Female | 47 | |
≤25 dB (normal) | 168 | |
26-40 dB (mild loss) | 2 | |
41-55 dB (moderate loss) | 0 | |
56-70 dB (moderate to severe loss) | 0 | |
71-90 dB (severe loss) | 0 | |
≥91 dB (profound loss) | 0 | |
≤ 25 dB (Sa1-S5, normal) | 168 | |
>25 dB (S6-S10, hearing loss candidate) | 2 |
aS: stratified hearing scale.
As the HST was used in our Ear Scale app for the default screening protocol, we also compared the HST with other popular protocols, including those suggested by the AAP and ASHA. The Ear Scale app was highly accurate at the tested frequencies (500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz) for all 3 screening protocols. The specificity was 100% and the sensitivity was 100% for HST (1000 Hz, 2000 Hz, and 4000 Hz at 20 dB and 500 Hz at 25 dB), 95.2% for AAP (500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz at 20 dB), and 95.2% for ASHA (500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz at 15 dB). The false-positive rate was 0% in all 3 screening protocols, whereas the false-negative rates were 0% of HST, 4.8% of AAP, and 4.8% of ASHA, respectively. A summary of the results from all 3 tested screening protocols is provided in
The correlation between the 2 measurements by utilizing the Ear Scale app in a quiet conference room and the clinical audiometer in a sound-treated room was significant at the .01 level (
The Hearing Scale Test and the mean difference between thresholds (dB) for the Ear Scale app and sound-treated booth (N=170 ears).
Ear Scale app with Hearing Scale Test | Sound-treated booth in pure-tone screening | ||
Mean (SD) | n | ||
≤5 dB (Sa1) | 4 (3.14) | 11 | |
6-10 dB (S2) | 7 (2.7) | 32 | |
11-15 dB (S3) | 8 (2.9) | 28 | |
16-20 dB (S4) | 11 (4.2) | 9 | |
21-25 dB (S5) | 14 (4.3) | 4 | |
26-30 dB (S6) | 0 | 0 | |
31-35 dB (S7) | 31 (NaNb) | 1 | |
36-40 dB (S8) | 0 | 0 | |
41-45 dB (S9) | 0 | 0 | |
46-50 dB (S10) | 0 | 0 | |
≤5 dB (S1) | 6 (2.1) | 5 | |
6-10 dB (S2) | 7 (3.3) | 26 | |
11-15 dB (S3) | 10 (2.6) | 31 | |
16-20 dB (S4) | 11 (3.8) | 18 | |
21-25 dB (S5) | 11 (2.6) | 4 | |
26-30 dB (S6) | 0 | 0 | |
31-35 dB (S7) | 0 | 0 | |
36-40 dB (S8) | 36 (NaN) | 1 | |
41-45 dB (S9) | 0 | 0 | |
46-50 dB (S10) | 0 | 0 | |
≤5 dB (S1) | 5 (2.9) | 16 | |
6-10 dB (S2) | 7 (3.0) | 58 | |
11-15 dB (S3) | 9 (2.8) | 59 | |
16-20 dB (S4) | 11 (3.8) | 27 | |
21-25 dB (S5) | 12 3.6) | 8 | |
26-30 dB (S6) | 0 | 0 | |
31-35 dB (S7) | 31 (NaN) | 1 | |
36-40 dB (S8) | 36 (NaN) | 1 | |
41-45 dB (S9) | 0 | 0 | |
46-50 dB (S10) | 0 | 0 |
aS: stratified hearing scale.
bNaN: not a number.
Comparison of the hearing screening protocols for both ears of all subjects participating in the study.
Results | Hearing screening protocols | ||
Hearing Scale Test, % | American Academy of Pediatrics, % | American Speech-Language-Hearing Association, % | |
Sensitivity | 100 | 95.2 | 95.2 |
Specificity | 100 | 100 | 100 |
False-positive | 0 | 0 | 0 |
False-negative | 0 | 4.8 | 4.8 |
The findings from this study support the use of the Ear Scale app in smartphone-based hearing screening of school children. To the best of our knowledge, this is the first report proposing a method for stratifying hearing test results on a smartphone and then using it for hearing screening in school children. As hearing screening is useful for detecting hearing impairment in the school system [
Many different ear screening protocols have been established in the past [
It is projected that the smartphone subscription will increase from 5 billion in 2018 to 7.2 billion in 2024 [
Our results indicate that the iOS-based Ear Scale app is reasonably accurate for hearing screening. The sensitivity and specificity were high (100%), whereas the false-positive (0%) and false-negative rates (0%) were low when the hearing tests were performed in a quiet room in the school library, ensuring an ideal test for hearing screening. The Ear Scale app was also found to be highly accurate in testing several hearing screening protocols in addition to the built-in HST [
The environmental noise level is one of the most common concerns in hearing screening [
This paper proposes an innovative approach to hearing screening of school-age children. We developed an Ear Scale app that is comparable with clinical-grade PTS in a sound-treated booth in terms of hearing test results. With favorable high sensitivity and specificity rates and low false-positive and false-negative rates, this study demonstrated that using the proposed Ear Scale app can rapidly screen hearing status and provide stratified test values for each screened ear, and it is therefore an ideal tool for hearing screening in schools.
American Academy of Pediatrics
American Speech-Language-Hearing Association
hearing level
Hearing Scale Test
International Organization for Standardization
no response
pure-tone average
pure-tone screening
reference equivalent threshold sound pressure level
stratified hearing scale
sound pressure level
The authors would like to thank Shang-Liang Wu, Hsin-Yi Huang, Wen-Tsung Kuo, the Big Data Center of Taipei Veterans General Hospital, and Biostatistics Task Force of Taipei Veterans General Hospital for their assistance during the study. This study was supported by grants from Taipei Veterans General Hospital (V107E-004-2(108), 108VACS-003, V108C-178) and the Ministry of Health and Welfare (MOHW108-TDU-B-211-124019, MOHW108-TDU-B-211-133001). The funders had no role in the study design, data collection and analysis, the decision to publish, or preparation of the manuscript.
YCC and WHL built the Ear Scale app and participated in writing the final draft. YCC and YFC designed the study, interpreted the results, and wrote the draft. YT and YHL and FL conceptualized and designed the study, interpreted the data, and critically revised the manuscript. All authors helped critically review and revise the manuscript and approved the final version.
None declared.