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.
Dear Karina,
Nice video! Do you have tips for other presenters what tools to use so they can also create such awesome video?
I also have two questions about your project. 1) What about the group of patients that might have less binaural benefit but not due to asymmetric hearing loss? I’m thinking due to cognitive constraints such as Agenesis of Corpus Callosum. But also attention disorder that result in a lower SRT, and hence in a false positive referral?
2) What equipment is needed to perform the test? Could you do this remotely or while waiting for your appointment at the doctor’s office?
Dear Jan-Willem,
Thank you for your interest in our study. There are quite a number of great programs available online. I used ‘Vyond’ for this video which I can recommend because it is very user friendly.
Indeed there will be people who may have limited binaural benefit or fail the test due to other underlying conditions, such as cognitive issues such or attention disorders. In general, because of the binaural paradigm, the test is quick to complete (< 3 minutes making it great as a direct to consumer self-test) and limits the constraints posed by attention issues. With the help of an adult, even children as young as 4 years have been shown to have reliable results. With rare disorders (such as agenesis of the corpus Callosum), yes it may be possible that a person fails the test. But we should also consider, that while not a peripheral hearing problem, central issues affecting speech-in-noise ability could also warrant referral.
Great question about the equipment! This is what I enjoy most about the digits-in-noise test. Because the test is presented at suprathreshold intensities, it does not rely on equipment calibration. In fact, we have been implementing this test as a free downloadable app on Android and iOS platforms for it to be used on smart devices like mobile phones and tablets (coupled with a set of earphones or headphones).
Can the authors spell out the rationale of using antiphasic stimuli in detecting SSD and conductive loss?
Dear Fang-Gang Zeng,
Sure. Previous binaural diotic versions were not able to detect unilateral sensorineural hearing loss since the results are a representation of the better ear. Furthermore, neither monaural or diotic versions sensitively detected conductive hearing loss (either unilateral or bilateral). Antiphasic presentation allows for very accurate detection of different types of hearing loss (including unilateral sensorineural or conductive hearing loss). Normal hearing listeners experience a release of masking in antiphasic conditions, thus obtain a better SRT. People with hearing loss (either bilateral or unilateral) on the other hand, have impaired antiphasic processing and have poorer SRTs than those with normal hearing.
This looks like a very good option moving forward. If we can just classify patient based on audiological or medical pathway, that will definitely shorten the journey duration and in current situation will shorten longer exposure in hospital.
Is this app freely available to download and try? I did do a quick search on android play store, but was not able to locate. Can you please provide further information on this. thank you in advance.
Thank you for the positive feedback Bebek. The categorization as described in this study is not available on the app yet, but you are welcome to try the antiphasic DIN version that is free to download. It has been incorporated by the World Health Organization as their official hearing test app, called hearWHO (available on Android and iOS platforms).
Feel free to let me know what you think about it!