Online Arabic and English Digits-in-Noise Tests: Effects of Test Language and At-Home Testing.

Purpose: The Digits-in-Noise (DIN) test is used widely in research and, increasingly, in remote hearing screening. The reported study aimed to provide basic evaluation data for browser-based DIN software, which allows remote testing without installation of an app. It investigated the effects of test language (Arabic vs. English) and test environment (lab vs. home) on DIN thresholds and test-retest reliability. It also examined the effects of test language on the correlations between DIN and audiometric thresholds.

Method: Fifty-two bilingual adults with normal hearing aged 18-35 years completed Arabic and English diotic DIN tests (two sessions in the lab and two sessions at home via the web). Effects of language and environment on DIN thresholds were assessed via paired t tests, while intraclass and Pearson's/Spearman's correlation coefficients quantified test-retest reliability and relations to audiometric thresholds.

Results: DIN thresholds were 0.74 dB higher (worse) for Arabic than English stimuli. Thresholds were 0.52 dB lower in the lab than at home, but the effect was not significant after correction for multiple comparisons. Intraclass and Pearson's correlation coefficients were too low for meaningful analysis due to the use of a normal-hearing sample with low between-subject variability in DIN and audiometric thresholds. However, exploratory analysis showed that absolute test-retest differences were low (< 1.2 dB, on average) for both languages and both test environments.

Conclusions: Arabic DIN thresholds were a little higher than English thresholds for the same listeners. Employing home-based rather than lab-based testing may slightly elevate DIN thresholds, but the effect was marginal. Nonetheless, both factors should be considered when interpreting DIN data. Test-retest differences were low for both languages and environments. To support hearing screening, subsequent research in audiometrically diverse listeners is required, testing the reliability of DIN thresholds and relations to hearing loss.