Reliability of Tablet-based Hearing Testing in Nicaraguan Schoolchildren: A Detailed Analysis

Extended High-Frequency Audiometry using the Wireless Automated Hearing Test System Compared to Manual Audiometry in Children and Adolescents

Objectives

Reliable wireless automated audiometry that includes extended high frequencies (EHF) outside a sound booth would increase access to monitoring programs for individuals at risk for hearing loss, particularly those at risk for ototoxicity. The purpose of the study was to compare thresholds obtained with 1) standard manual audiometry to automated thresholds measured with the Wireless Automated Hearing Test System (WAHTS) inside a sound booth, and 2) automated audiometry in the sound booth to automated audiometry outside the sound booth in an office environment.

Design

Cross-sectional, repeated measures study. Twenty-eight typically developing children and adolescents (mean = 14.6 yrs; range = 10 to 18 yrs). Audiometric thresholds were measured from 0.25 to 16 kHz with manual audiometry in the sound booth, automated audiometry in the sound booth, and automated audiometry in a typical office environment in counterbalanced order. Ambient noise levels were measured inside the sound booth and the office environment were compared to thresholds at each test frequency.

Results

Automated thresholds were overall about 5 dB better compared to manual thresholds, with greater differences in the extended high frequency range (EHF;10-16 kHz). The majority of automated thresholds measured in a quiet office were within ± 10 dB of automated thresholds measured in a sound booth (84%), while only 56% of automated thresholds in the sound booth were within ± 10 dB of manual thresholds. No relationship was found between automated thresholds measured in the office environment and the average or maximum ambient noise level.

Conclusions

These results indicate that self-administered, automated audiometry results in slightly better thresholds overall than manually administered audiometry in children, consistent with previous studies in adults. Ambient noise levels in a typical office environment did not have an adverse effect on audiometric thresholds measured using noise attenuation headphones. Thresholds measured using an automated tablet with noise attenuating headphones could improve access to hearing assessment for children with a variety of risk factors. Additional studies of extended high frequency automated audiometry in a wider age range are needed to establish normative thresholds.

Test-Retest repeatability of automated threshold audiometry in Nicaraguan schoolchildren

OBJECTIVE

Automated threshold audiometry (ATA) could increase access to paediatric hearing assessment in low- and middle-income countries, but few studies have evaluated test-retest repeatability of ATA in children. This study aims to analyse test-retest repeatability of ATA and to identify factors that affect the reliability of this method.

DESIGN

ATA was performed twice in a cohort of Nicaraguan schoolchildren. During testing, the proportion of responses occurring in the absence of a stimulus was measured by calculating a stimulus response false positive rate (SRFP). Absolute test-retest repeatability was determined between the two trials, as well as the impact of age, gender, ambient noise, head circumference, and SRFP on these results.

STUDY SAMPLE

807 children were randomly selected from 35 schools in northern Nicaragua.

RESULTS

Across all frequencies, the absolute value of the difference between measurements was 5.5 ± 7.8 dB. 89.6% of test-retest differences were within 10 dB. Intra-class correlation coefficients between the two measurements showed that lower SRFP was associated with improved repeatability. No effect of age, gender, or ambient noise was found.

CONCLUSIONS

ATA produced moderate test-retest repeatability in Nicaraguan schoolchildren. Participant testing behaviours, such as delayed or otherwise inappropriate response patterns, significantly impacts the repeatability of these measurements.

Field assessment of acute auditory responses to environmental exposures in close quarters tactics training

OBJECTIVE

The purpose of this study was to evaluate auditory performance of military instructors as part of a training course involving noise and blast exposure. Boothless audiometry was used to estimate the test-retest reliability of the auditory measures under realistic field conditions and to determine risk of acute auditory injury during standard training practices.

DESIGN AND STUDY SAMPLE

Thirteen U.S. Marine instructors participated in study activities. An audiologic testing suite embedded in a noise-attenuating headset was used to test various tone detection tasks on subjects after exposure. Acoustic exposures were captured with sound level meters.

RESULTS

Boothless audiometry provide highly repeatable results for various tests of auditory performance in the field environment. In this test population, changes in auditory performance pre- and post-noise exposure were minimal for most measures. The notable exception was binaural (NoSπ) tone detection, which showed significant degradations both as a function of pre- and post-noise exposure on the same day and as a result of cumulative noise exposure over the period of the study.

CONCLUSIONS

Study outcomes are consistent with prior laboratory and epidemiological work and suggest a link between the binaural processes required for NoSπ detection and the hearing-related issues reported by blast-exposed service members.

School Hearing Screening With a Portable, Tablet-Based, Noise-Attenuating Audiometric Headset in Rural Nicaragua

OBJECTIVE

To investigate the utility and effectiveness of a noise-attenuating, tablet-based mobile health system combined with asynchronous telehealth evaluations for screening rural Nicaraguan schoolchildren for hearing loss.

STUDY DESIGN

Prospective population-based survey.

SETTING

Rural Nicaraguan communities.

PATIENTS

There were 3,398 school children 7 to 9 years of age.

INTERVENTIONS

Diagnostic automated and manual audiometry, detailed asynchronous telehealth evaluations.

MAIN OUTCOME MEASURES

Referral rates, ambient noise levels, and audiometric results as well as hearing loss prevalence, types, and risk factors.

RESULTS

Despite high ambient noise levels during screening (46.7 dBA), no effect of noise on referral rates on automated audiometry or confirmatory manual audiometry in those who failed automated testing was seen. The overall audiometric referral rate was 2.6%. Idiopathic sensorineural hearing loss (SNHL) and cerumen impaction were the most common types of hearing loss in this population with an estimated prevalence of hearing loss (all types) of 18.3 per 1,000 children. SNHL was associated with both drug exposure during pregnancy (p = 0.04) and pesticide exposure in the home (p = 0.03).

CONCLUSION

Hearing screening using a tablet-based, noise-attenuating wireless headset audiometer is feasible and effective in rural low-resource environments with moderately elevated ambient noise levels. The referral rate with noise-attenuating headsets was much lower than that previous reports on this population. In addition, manual audiometry resulted in much lower referral rates than automated audiometry. The confirmed hearing loss rate in this study is comparable to reports from other low-income countries that use some form of noise attenuation during screening. Pesticide exposure and drug exposure during pregnancy are potential causes of SNHL in this population.

Clinical comparison of two automated audiometry procedures

Objective

Automated pure-tone audiometry has been shown to provide similar hearing threshold estimates to conventional audiometry, but lower correlations were reported at high and low frequencies in audiometric tests than those of manual tests, while the correlations were better in the middle frequencies. In this paper, we used the same equipment and different test procedures for automated testing, and compared the results with manual test results.

Design

One hundred subjects aged 18–36 years were randomly divided into two groups to perform air-conduction pure-tone audiometry (0.25, 0.5, 1, 2, 4, 8 kHz) using the ascending and shortened ascending protocols built-in to the automated audiometer, respectively. Recorded testing time, the total number of responses and the subject’s preference tests were compared with those of manual tests.

Results

Significant difference was found at 250 Hz regarding the distribution of the absolute difference between the two automated and the manual thresholds. The testing time spend in the ascending method (9.8 ± 1.4 min, mean ± SD) was significantly longer than in the shorted ascending method (5.8 ± 0.9 min). The total numbers of responses of the ascending method (90.5 ± 10.8 times) and shorted ascending method (62.0 ± 11.4 times) were significantly different. Finally, no significant difference was found in preferences between automated and manual procedures.

Conclusion

The shorted ascending method can save lots of testing time. The difference between the two automated thresholds at 250 Hz is caused by the different test procedures, and the difference at 8,000 Hz between the automated test and the manual test can be due to the transducer types and allowable differences in calibration.

Community health workers and mHealth systems for hearing screening in rural Nicaraguan schoolchildren

Background

We aimed to investigate the effectiveness of using minimally trained community health workers (CHW) to screen schoolchildren in rural Nicaragua for hearing loss using a tablet-based audiometric system integrated with asynchronous telehealth evaluations and mobile health (mHealth) appointment reminders.

Methods

A population-based survey was conducted using community health workers (CHWs) to perform tablet-based audiometry, asynchronous telehealth evaluations, and mHealth reminders to screen 3398 school children (7-9 years of age) in 92 rural Nicaraguan communities. The accuracy of screening, test duration, testing efficiency, telehealth data validity, and compliance with recommended clinic visits were analyzed.

Results

Minimally trained CHWs successfully screened children within remote rural schools with automated audiometry (test duration = 5.8 minutes) followed by manual audiometry if needed (test duration = 4.3 minutes) with an estimated manual audiometry validity of 98.5% based on a review of convergence patterns. For children who were referred based on audiometry, the otoscopy and tympanometry obtained during telehealth evaluations were high quality (as reviewed by 3 experts) in 44.6% and 80.1% of ears, respectively. A combination of automated short message service (SMS) text messages and voice reminders resulted in a follow-up compliance of 75.2%. No families responded to SMS messages alone.

Conclusions

Tablet-based hearing screening administered by minimally trained CHWs is feasible and effective in low- and middle-income countries. Manual audiometry was as efficient as automated audiometry in this setting. The physical exam tasks of otoscopy and tympanometry require additional training. Mobile phone messages improve compliance for confirmatory audiometry, but the utility of SMS messaging alone is unclear in this population.

Software Application toward Accessible Hearing Care Assessment: Gap in Noise Test

Currently, several methods are being applied to assess auditory temporal resolution in a controlled clinical environment via the measurements of gap detection thresholds (GDTs). However, these methods face two issues: the relatively long time required to perform the gap detection test in such settings and the potential of inaccessibility to such facilities. This article proposes a fast, affordable, and reliable application-based method for the determination of GDT either inside or outside the soundproof booth. The proposed test and the acoustic stimuli were both developed using the MATLAB® programming platform. GDT is determined when the subject is able to distinguish the shortest silent gap inserted randomly in one of two segments of white noise. GDTs were obtained from 42 normal-hearing subjects inside and outside the soundproof booth. The results of this study indicated that average GDTs measured inside the booth (5.12 ± 1.02 ms) and outside (4.78 ± 1.16 ms) were not significantly different. The measured GDTs were also comparable to that reported in the literature. In addition, the GDT screening time of the proposed method was approximately 5 minutes, a screening time that is much less than that reported by the literature. Data show that the proposed application was fast and reliable to screen GDT compared to the standard method currently used in clinical settings.

Digital approaches to automated and machine learning assessments of hearing: a scoping review (Preprint)

Background

Hearing loss affects 1 in 5 people worldwide and is estimated to affect 1 in 4 by 2050. Treatment relies on the accurate diagnosis of hearing loss; however, this first step is out of reach for >80% of those affected. Increasingly automated approaches are being developed for self-administered digital hearing assessments without the direct involvement of professionals.

Objective

This study aims to provide an overview of digital approaches in automated and machine learning assessments of hearing using pure-tone audiometry and to focus on the aspects related to accuracy, reliability, and time efficiency. This review is an extension of a 2013 systematic review.

Methods

A search across the electronic databases of PubMed, IEEE, and Web of Science was conducted to identify relevant reports from the peer-reviewed literature. Key information about each report’s scope and details was collected to assess the commonalities among the approaches.

Results

A total of 56 reports from 2012 to June 2021 were included. From this selection, 27 unique automated approaches were identified. Machine learning approaches require fewer trials than conventional threshold-seeking approaches, and personal digital devices make assessments more affordable and accessible. Validity can be enhanced using digital technologies for quality surveillance, including noise monitoring and detecting inconclusive results.

Conclusions

In the past 10 years, an increasing number of automated approaches have reported similar accuracy, reliability, and time efficiency as manual hearing assessments. New developments, including machine learning approaches, offer features, versatility, and cost-effectiveness beyond manual audiometry. Used within identified limitations, automated assessments using digital devices can support task-shifting, self-care, telehealth, and clinical care pathways.