Discrimination of degrees of auditory performance from the digits-in-noise test based on hearing status.

ABSTRACT

OBJECTIVE: To discriminate among degrees of auditory performance of the Digits-in-Noise (DIN) test. DESIGN: We performed Pearson's correlations and age- and sex-adjusted linear regression models to examine the correlation between pure-tone average (PTA) from pure-tone audiometric tests and speech recognition thresholds (SRT) from the DIN test. Then, optimal SRT cut-points by PTA-defined hearing status (0-25 dB HL [normal], 26-40 dB HL [mild hearing loss], 41-50 dB HL [moderate hearing loss]) were compared across three methods: Youden, Nearest, and Liu. SRT-defined categories of auditory performance were compared to PTA-defined hearing categories to examine the convergence of similar categories. Study Sample 3422 Rotterdam Study participants aged 51-98 years between 2011 and 2014. RESULTS: The correlation between SRT and PTA was 0.65 (95% Confidence Interval 0.63, 0.67) in the overall sample. The variability of SRT explained by PTA after age and sex adjustment was 54%. Optimal cut-points for the overall sample across the three methods were ≤ -5.55 dB SNR (normal); > -5.55 to ≤ -3.80 dB SNR (insufficient performance); > -3.80 dB SNR (poor performance). When comparing the SRT- or PTA-defined categories, 59.8% had concordant hearing categories and 40.2% had discordant hearing categories. CONCLUSIONS: Discrimination of degrees of auditory performance may add greater utility of the DIN test.