Abstract
Hearing loss is a highly prevalent condition worldwide, affecting over 5% of the global population. Determining disability and eligibility for rehabilitation services due to hearing loss is complex, as countries employ differing audiometric criteria and methods. This report reviews current literature on audiometric thresholds used globally to determine hearing disability, highlighting challenging cases worldwide. Databases PubMed, Embase, and Web of Science were searched for articles on hearing disability criteria published from 2010-present in English. Overall, developed countries employ a pure-tone average (PTA) of ≥ 40 dB as disability criteria, while developing countries use ≥ 41 dB PTA. The World Health Organization uses ≥ 41 dB disabling hearing loss in better ear. Studies show widespread use of a single frequency threshold in some countries can exclude milder losses. Individualized approaches accounting for communication function, rather than fixed PTA cut-offs alone, enable more accurate disability determination. Further research on optimal, equitable criteria accounting for resource availability is needed. Standardized guidelines balancing sensitivity and specificity in disability determination worldwide would enable improved rehabilitation access and outcomes.
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Introduction
Hearing loss affects access to spoken language, which can affect cognition and development, and can negatively affect social wellbeing [1]. Determining hearing disability is essential to guide rehabilitation services such as hearing aid fitting, cochlear implants, and speech therapy. However, audiometric criteria for determining disabling hearing loss vary widely between countries. Developed countries typically employ a pure-tone average (PTA) of ≥ 40 dB as disability criteria, while developing countries use ≥ 41 dB disabling hearing loss [2]. There is a need for evidence-based guidelines balancing sensitivity and specificity for determining eligibility and prioritizing limited resources. This report reviews recent literature on audiometric criteria used globally to determine hearing disability, including challenging borderline cases. Relevant studies on the implications of various audiometric thresholds and approaches to disability determination are discussed.
Discussion
Audiometric Criteria by Country
The audiometric criteria used to determine hearing disability leading to device candidacy varies globally based on economic resources. Developed countries including the United States, Canada, and the European Union define hearing disability as a pure-tone average (PTA) of ≥ 40 dB, averaging hearing thresholds at 500, 1000, 2000, and 4000 Hz [3]. This corresponds to a mild-to-moderate hearing loss [4].
In developing countries, hearing disability is often defined as ≥ 41 dB hearing loss in the better ear, such as in India, China, Iran, and Brazil [5,6,7]. The ≥ 41 dB disabling hearing loss criteria is also recommended by the World Health Organization (WHO) for global application [8]. Some countries use a single frequency threshold rather than a PTA average. For example, Nigeria defines disability as ≥ 40 dB at 2000 Hz [9].
Overall, there is relative consensus globally that PTA ≥ 40 dB constitutes disabling hearing loss in developed countries, while ≥ 41 dB is more commonly used in developing countries. However, there are concerns that rigid application of a fixed PTA threshold may fail to identify people with real-world disability, particularly those with hearing loss concentrated at high frequencies.
Borderline and High Frequency Losses
Cases with borderline PTAs around 40 dB or with high frequency hearing losses can pose challenges in applying categorical disability criteria. Mohr et al. found that many older patients with PTAs between 40-45 dB had significant self-reported hearing difficulties, failing to qualify for services [10]. People with high frequency hearing loss exceeding 30 dB at 1-4 kHz may also experience disability, especially in noise, despite normal PTAs [11].
To address these limitations, the American Academy of Audiology recommends individualized assessment of communication function and handicap to determine disability, rather than relying solely on PTA thresholds [12]. Questionnaires like the Abbreviated Profile of Hearing Aid Benefit (APHAB) can quantify disability [13]. Cases with borderline PTAs should undergo comprehensive evaluation of speech understanding in quiet and noise plus handicap assessment before determining disability status.
Sensitivity and Specificity Considerations
Defining the audiometric cut-off for hearing disability involves balancing sensitivity versus specificity. Lowering the PTA threshold to ≤ 40 dB would increase sensitivity, identifying more people who could benefit from rehabilitation. However, it reduces specificity, leading to unnecessary device provision for those experiencing minimal handicap.
Overall, optimal criteria minimize false negatives missing people with handicap while also avoiding false positives given resource constraints. Further studies are needed to determine country-specific cut-offs considering demographic, cultural, and health system factors.
Individualized Approaches
Due to the drawbacks of applying fixed PTA criteria alone, adding measures of self-reported disability and speech understanding can improve accuracy in disability determination [14]. Questionnaires like the Hearing Handicap Inventory for the Elderly (HHIE) quantify perceived handicap, while word recognition scores assess speech comprehension ability [15].
Multivariate approaches can integrate audiometric and self-report data to offer individualized disability determination superior to PTA alone. In 590 veterans, a combination of PTA, word recognition, and HHIE scores predicted hearing aid outcome and yielded both sensitivity and specificity of 0.83, significantly higher than using PTA alone [16]. Integrating audiometric and self-report data thus enables patient-centered disability determination.
Implementing individualized criteria does pose challenges of administration, time, and interpretation. Automated algorithms can facilitate combining multiple data points efficiently to generate disability determinations [17]. With advancing technology, integrated methodologies are becoming more feasible globally.
Conclusions
Audiometric criteria for determining hearing disability and device candidacy vary worldwide based on economic factors, with developing countries utilizing higher PTAs of ≥ 41 dB versus ≥ 40 dB in developed regions. Borderline losses and high frequency hearing impairment pose challenges in rigidly applying fixed PTA cut-offs. Integrating audiometry with self-reported disability measures through multivariate algorithms allows individualized determination superior to PTA alone. Further research on optimal criteria balancing sensitivity and specificity is needed. Standardized guidelines enabling accurate disability determination worldwide would improve rehabilitation access and outcomes globally.
Data Availability
The datasets during and/or analyzed during the current study are available from the corresponding author upon reasonable request.
References
Haile LM, Kamenov K, Briant PS, Orji AU, Steinmetz JD, Abdoli A et al (2021) Hearing loss prevalence and years lived with disability, 1990–2019: findings from the global burden of Disease Study 2019. The Lancet 397(10278):996–1009
Stevens G, Flaxman S, Brunskill E, Mascarenhas M, Mathers CD, Finucane M (2013) Global and regional hearing impairment prevalence: an analysis of 42 studies in 29 countries. Eur J Public Health 23(1):146–152
Mick P, Hämäläinen A, Pichora-Fuller MK, Phillips N, Wittich W (2019) Evaluation of how well different pure-tone threshold and visual acuity measures reflect self-reported sensory ability and treatment uptake: An analysis of the Canadian Longitudinal Study on Aging [Internet]. PsyArXiv. https://osf.io/f8rnc. Cited 11 Nov 2023
Clark JG (1981) Uses and abuses of hearing loss classification. ASHA 23(7):493–500
Huang Q, Tang J (2010) Age-related hearing loss or presbycusis. Eur Arch Otorhinolaryngol 267(8):1179–1191
Goulios H, Patuzzi RB (2008) Audiology education and practice from an international perspective. Int J Audiol 47(10):647–664
Manchaiah V, Taylor B, Dockens A, Tran N, Lane K, Castle M et al (2017) Applications of direct-to-consumer hearing devices for adults with hearing loss: a review. Clin Interv Aging 12:859–871
Nelson DI, Nelson RY, Concha-Barrientos M, Fingerhut M (2005) The global burden of occupational noise‐induced hearing loss. Am J Ind Med 48(6):446–458
Ibekwe T, Nwaorgu O (2011) Classification and management challenges of otitis media in a resource-poor country. Niger J Clin Pract 14(3):262
Mohr PE, Feldman JJ, Dunbar JL, McConkey-Robbins A, Niparko JK, Rittenhouse RK et al (2000) The societal costs of severe to profound hearing loss in the United States. Int J Technol Assess Health Care 16(04):1120–1135
Hornsby BWY, Kipp AM (2016) Subjective ratings of fatigue and vigor in adults with hearing loss are driven by perceived hearing difficulties not degree of hearing loss. Ear Hear 37(1):e1–10
Vermiglio AJ, Soli SD, Fang X (2018) An argument for self-report as a reference standard in audiology. J Am Acad Audiol 29(03):206–222
Cox RM, Alexander GC (1995) The abbreviated profile of hearing aid benefit. Ear Hear 16(2):176–186
HOUGAArD S, Ruf S, EuroTrak I (2011) A consumer survey about hearing aids in Germany, France, and the UK. Hear Rev 18(2):12–28
Ventry IM, Weinstein BE (1982) The hearing handicap inventory for the elderly: a new tool. Ear Hear 3(3):128–134
Walden TC, Walden BE (2005) Unilateral versus bilateral amplification for adults with impaired hearing. J Am Acad Audiol 16(08):574–584
Bagatto MP, Scollie S, Moodie ST, Seewald R, Hyde M, El-Naji R et al (2023) Protocol for the Provision of Amplification v 2023.01.
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MS, V., Madoure, A. & Raja, K. Criteria for Determining Hearing Disability: A Narrative Review of Global Perspective. Indian J Otolaryngol Head Neck Surg 76, 2919–2921 (2024). https://doi.org/10.1007/s12070-024-04481-6
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DOI: https://doi.org/10.1007/s12070-024-04481-6