Authors: Karina C. De Sousa1 , Cas Smits2 , David R. Moore3,4 , Hermanus C. Myburgh5 , De Wet Swanepoel1,6
1Department of Speech-Language Pathology and Audiology, University of Pretoria, Pretoria, Gauteng, South Africa.
2Amsterdam UMC, Vrije Universiteit Amsterdam, Otolaryngology-Head and Neck Surgery, Ear and Hearing, Amsterdam Public Health research institute, De Boelelaan 1117, Amsterdam.
3Communication Sciences Research Center, Cincinnati Childrens’ Hospital Medical Center and University of Cincinnati, Ohio, USA.
4Manchester Centre for Audiology and Deafness, University of Manchester, United Kingdom.
5Department of Electrical, Electronic and Computer Engineering, University of Pretoria, Pretoria, Gauteng, South Africa.
6Ear Sciences Centre, School of Surgery, University of Western Australia, Nedlands, Australia.
Background: The digits-in-noise (DIN) test has become a popular hearing screening test globally available directly to the public using mobile technology. A recent antiphasic digits-in-noise (DIN) test paradigm can detect bilateral sensorineural (SNHL), unilateral SNHL and conductive hearing loss (CHL) using the 3 minute test. While the previous diotic DIN (i.e. identically phased digits presented in masking noise) did not detect either unilateral SNHL or CHL, a combination of antiphasic and diotic versions could detect and categorise hearing loss type. Screening measures that can triage cases and direct referral for either diagnostic hearing assessment or medical evaluation could optimise diagnosis and treatment pathways. The aim of this project was, therefore, to determine the suitability of the diotic and antiphasic DIN as a screening measure to detect and triage types of hearing loss.
Method: The sample consisted of 393 adult participants with varying types and degrees of hearing ability measured conventionally with air- and bone-conduction audiometry were found to have (i) normal bilateral hearing (n=202), (ii) bilateral SNHL (n=123) or (iii) unilateral or CHL (n=68). All these participants completed both an antiphasic and diotic test.
Results: The antiphasic DIN had higher area under the curve (0.94; AUROC) than diotic DIN (0.79) to detect hearing loss more than 25 dB HL (of any type) in the poorer ear. In a sequential antiphasic and diotic DIN procedure, fixed cut-offs could accurately place 75% of all participants in their respective hearing categories. A maximum likelihood estimation using varying diotic SRT and a fixed antiphasic cut-off, could correctly detect and classify 79% of all hearing loss types.
Conclusions: Hearing loss can be classified into three categories (normal hearing, bilateral SNHL, unilateral SNHL or CHL) with reasonable accuracy using self-administered DIN testing alone. This would allow for directed referrals to either a medical doctor (i.e. unilateral SNHL or CHL) or audiologist (bilateral SNHL), optimizing resource allocation in constrained healthcare settings.