Other example reports ( tutorials / technical issues / workarounds )

Telephone- or web-administered tests of hearing loss.

There is a large recent literature dealing with telephone- or web-administered tests of hearing loss that describes many examples of valid and reliable tests of hearing using spoken digits in noise (rather than pure-tone testing) that do not require calibrated equipment to administer. Most of this literature has been motivated by the initial findings of Cas Smits and his colleagues in the Netherlands, based on measurements of the SNR thresholds for correct identification of spoken three-digit sequences presented in noise. Smits and colleagues showed that such tests are significantly correlated with average pure-tone thresholds in the speech-frequency range, and even more strongly with other speech-in-noise tests. Research on remotely administered digit-in-noise (DIN) tests has addressed many of the issues of concern to this Task Force, including variability introduced by differences in hearing instruments and in test environments and the efficiency and validity of self-administered tests. Results of validation studies demonstrate that self-testing for hearing loss can be quite valid, although there is a host of self-tests currently offered to the public with little or no evidence of validation. Both hearing clinicians and the general public would benefit if some agency, such as the FDA, were to develop validity criteria for such tests.

A DIN test has been available in the US for nearly ten years (the National Hearing Test), which is administered by telephone. The NHT was developed with NIH support and validated in an extensive collaboration with three Veterans Administration hearing centers. Like many of the telephone-based DIN tests, the NHT uses an automated Interactive Voice Response system to present spoken digits in noise, adaptively adjust the SNR, based on a caller’s responses (entered via the telephone keypad), and compute a threshold SNR. Feedback about the caller’s hearing is provided in three categories: within the normal range, slightly below the normal range, or substantially below the normal range. Over 160,000 persons have now been tested with the NHT, providing a unique corpus of data on the demographics of hearing loss in the US. Similar tests have now been developed and validated in the UK, most European countries, Australia, and South Africa.

Charles S. Watson, Ph.D.

Gary R. Kidd, Ph.D.

Indiana University and

Communication Disorders Technology, Inc.


The literature referred to in this comment includes 30+ articles on digit-in-noise tests published in the past 15 years, of which the following is a small ample:

De Sousa K.C., Swanepoel, W., Moore, D.R., Myburgh, H./C, and Smits, C. (2020) Improving Sensitivity of the Digits-In-Noise Test Using Antiphasic Stimuli. Ear Hear.;41(2):442-450.Denys, S., Hofmann, M., Luts, H., Guérin, C., Keymeulen, A., van Hoeck, K., van Wieringen, A., Hoppenbrouwers, K. and Wouters, J. (2018). “School-Age Hearing Screening Based on Speech-in-Noise Perception Using the Digit Triplet Test.” Ear and Hearing 39:1104–15.Smits, C., Kapteyn, T.S., and Houtgast, T. (2004) “Development and Validation of an Automatic Speech-in-Noise Screening Test by Telephone.” International Journal of Audiology 43:15–28.Smits, C. and Houtgast, T. (2007). “Recognition of Digits in Different Types of Noise by Normal and Hearing and Hearing-Impaired Listeners.” International Journal of Audiology 46(3):134–44.Smits, C., Watson, C. S., Kidd, G. R., Moore, D. R. and Goverts, S. T. (2016). “A Comparison between the Dutch and American- English Digits-in-Noise ( DIN ) Tests in Normal-Hearing Listeners.” International Journal of Audiology 55(6):358–65.Watson, C. S., Kidd, G. R., Miller, J. D., Smits, C. and Humes, L. E. (2012) Telephone screening tests for functionally impaired hearing: Current use in seven countries and development of a US version. J. Am. Acad. Audiol. 23, 757-767.

Williams-Sanchez, V., McArdle, R.A., Wilson, R.H., Kidd, G.R., Watson, C.S., Bourne, A.L. (2014) Validation of a screening test of auditory function using the telephone. J. Am. Acad. Aud. ;25:937–951.