A user-operated audiometry method based on the maximum likelihood principle and the two-alternative forced-choice paradigm

Development and evaluation of a novel user-operated slider-based audiometry method

OBJECTIVE

To evaluate a novel user-operated audiometry method allowing users full control in determining their pure-tone hearing thresholds.

DESIGN

Comparative study. Participants were recruited from a hearing clinic after undergoing manual audiometry (six frequencies). They then performed test-retests of a new test (slider audiometry, eight frequencies) and completed the System Usability Scale questionnaire.

STUDY SAMPLE

37 adult participants, including 30 hearing-impaired and seven normal-hearing individuals.

RESULTS

Mean (SD) threshold differences for octave frequencies between 250 to 2000 Hz between manual and slider audiometry ranged from -7.8 (6.6) to -5.7 (6.5) dB and were significant. For 4000 and 8000 Hz mean differences were -0.3 (8.4) and 0.0 (9.7) dB and insignificant. Standard deviations ranged from 6.5 to 9.7 dB across six tested frequencies. Slider test-retest mean threshold differences ranged from -1.4 (4.7) to 0.3 (6.0) dB across eight tested frequencies, with standard deviations ranging from 4.1 to 8.5 dB. The average usability score for the slider audiometry was 88.3.

CONCLUSION

When compared to manual audiometry, the slider audiometry demonstrated validity at 4000 and 8000 Hz but found significantly lower thresholds for octave frequencies between 250 to 2000 Hz. Test-retests of the new method revealed small mean differences and acceptable SDs.

AMTASTM and user-operated smartphone research application audiometry-An evaluation study

OBJECTIVE

To evaluate two user-operated audiometry methods, the AMTASTM PC-based audiometry and a low-cost smartphone audiometry research application (R-App).

DESIGN

A repeated-measures within-subject study design was used to compare both user-operated methods to traditional manual audiometry and to evaluate test-retest reliability of each method.

STUDY SAMPLE

58 subjects were recruited in the study of which 83 ears had normal hearing thresholds and 33 ears had hearing loss (pure-tone average > 25 dB HL). Average age of participants was 44.8 years, with an age range of 11-85.

RESULTS

Standard deviation of absolute differences ranged between 3.9-6.9 dB on AMTASTM and 4.5-6.8 dB on the R-App. The highest variability was found at the 8000 Hz frequency (R-App and AMTASTM test) and 3000 Hz frequency (AMTASTM retest). Evaluation of test-retest reliability of AMTASTM and R-App showed SD of absolute differences ranging between 3.5-5.8 dB and 3.1-5.0 dB, respectively. The mean threshold difference between test and retest was within ±1.5 dB on AMTASTM and ±1 dB on the R-App.

CONCLUSION

Accuracy of AMTASTM and the R-App was within acceptable limits for audiometry and comparable to traditional manual audiometry on all tested frequencies (250-8000 Hz). Evaluation of test-retest reliability showed acceptable variation on both AMTASTM and R-App. Both user-operated methods could be reliably performed in a quiet non-soundproofed environment.

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.

Digital Approaches to Automated and Machine Learning Assessments of Hearing: Scoping Review

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.

Utilizing True Wireless Stereo Earbuds in Automated Pure-Tone Audiometry

True wireless stereo (TWS) earbuds have become popular and widespread in recent years, and numerous automated pure-tone audiometer applications have been developed for portable devices. However, most of these applications require specifically designed earphones to which the public may not have access. Therefore, the present study investigates the accuracy of automated pure-tone audiometry based on TWS earbuds (Honor FlyPods). The procedure for developing an automated pure-tone audiometer is reported. Calibration of the TWS earbuds was accomplished by electroacoustic measurements and establishing corrected reference equivalent threshold sound pressure levels. The developed audiometer was then compared with a clinical audiometer using 20 hearing-impaired participants. The average signed and absolute deviations between hearing thresholds measured using the two audiometers were 3.1 dB and 6.7 dB, respectively. The overall accuracy rate in determining the presence/absence of hearing loss was 81%. The results show that the proposed procedure for an automated air-conduction audiometer based on TWS earbuds is feasible, and the system gives accurate hearing level estimation using the reported calibration framework.

User-Operated Audiometry Project (UAud) - Introducing an Automated User-Operated System for Audiometric Testing Into Everyday Clinic Practice

Hearing loss is the third leading cause of years lived with disability. It is estimated that 430 million people worldwide are affected, and the number of cases is expected to increase in the future. There is therefore increased pressure on hearing health systems around the world to improve efficiency and reduce costs to ensure increased access to quality hearing health care. Here, we describe the User-Operated Audiometry project, the goal of which is to introduce an automated system for user-operated audiometric testing into everyday clinic practice as a means to relieve part of this pressure. The alternative to the existing referral route is presented in which examination is executed via the user-operated system. This route is conceptualized as an interaction between the patient, the system, and the hearing care professional (HCP). Technological requirements of the system and challenges that are related to the interaction between patients, the user-operated system, and the HCPs within the specific medical setting are discussed. Lastly, a strategy for the development and implementation of user-operated audiometry is presented, which includes initial investigations, a validation study, and implementation in a real-life clinical situation.

Tinnitus Severity Is Related to the Sound Exposure of Symphony Orchestra Musicians Independently of Hearing Impairment

Objectives:

Tinnitus can be debilitating and with great impact of musicians professional and private life. The objectives of the study were therefore to: (1) describe the epidemiology of tinnitus including its severity in classical orchestra musicians, (2) investigate the association between tinnitus severity in classical musicians and their cumulative lifetime sound exposure, and (3) the association between tinnitus and hearing thresholds.

Design:

The study population included all musicians from five Danish symphony orchestras. Answers regarding their perception of tinnitus were received from 325 musicians, and 212 musicians were also tested with audiometry. Any tinnitus and severe tinnitus were two definitions of tinnitus used as outcomes and analyzed in relation to an estimation of the cumulative lifetime sound exposure from sound measurements and previously validated questionnaires and the average hearing threshold of 3, 4, and 6 kHz.

Results:

Thirty-five percentage of all musicians (31% female and 38% of male musicians) reported having experienced at least one episode of tinnitus lasting for more than 5 minutes during their life. Severe tinnitus with a severe impact on daily life was reported by 19% of the musicians (18% of female and 21% of male musicians). The severity of tinnitus was associated with increased lifetime sound exposure but not to poorer high frequency hearing thresholds when the lifetime sound exposure was considered. The odds ratio for an increase in one unit of tinnitus severity was 1.25 (95% CI, 1.12–1.40) for every 1 dB increase in lifetime sound exposure.

Conclusion:

Musicians frequently report tinnitus. Any tinnitus and severe tinnitus are significantly associated with the cumulative lifetime sound exposure, which was shown to be the most important factor not only for the prevalence but also for the severity of tinnitus—even in musicians without hearing loss. High-frequency hearing thresholds and tinnitus severity were correlated only if the cumulative lifetime sound exposure was excluded from the analyses.

Noise exposure during prehospital emergency physicians work on Mobile Emergency Care Units and Helicopter Emergency Medical Services

BACKGROUND

Prehospital personnel are at risk of occupational hearing loss due to high noise exposure. The aim of the study was to establish an overview of noise exposure during emergency responses in Mobile Emergency Care Units (MECU), ambulances and Helicopter Emergency Medical Services (HEMS). A second objective was to identify any occupational hearing loss amongst prehospital personnel.

METHODS

Noise exposure during work in the MECU and HEMS was measured using miniature microphones worn laterally to the auditory canals or within the earmuffs of the helmet. All recorded sounds were analysed in proportion to a known tone of 94 dB. Before and after episodes of noise exposure, the physicians underwent a hearing test indicating whether the noise had had any impact on the function of the outer sensory hair cells. This was accomplished by measuring the amplitude level shifts of the Distortion Product Otoacoustic Emissions. Furthermore, the prehospital personnels' hearing was investigated using pure-tone audiometry to reveal any occupational hearing loss. All prehospital personnel were compared to ten in-hospital controls.

RESULTS

Our results indicate high-noise exposure levels of ≥80 dB(A) during use of sirens on the MECU and during HEMS operations compared to in-hospital controls (70 dB(A)). We measured an exposure up to ≥90 dB(A) under the helmet for HEMS crew. No occupational hearing loss was identified with audiometry. A significant level shift of the Distortion Product Otoacoustic Emissions at 4 kHz for HEMS crew compared to MECU physicians was found indicating that noise affected the outer hair cell function of the inner ear, thus potentially reducing the hearing ability of the HEMS crew.

DISCUSSION

Further initiatives to prevent noise exposure should be taken, such as active noise reduction or custom-made in-ear protection with communication system for HEMS personnel. Furthermore, better insulation of MECU and ambulances is warranted.

CONCLUSION

We found that the exposure levels exceeded the recommendations described in the European Regulative for Noise, which requires further protective initiatives. Although no hearing loss was demonstrated in the personnel of the ground-based units, a reduced function of the outer sensory hair cells was found in the HEMS group following missions.