Test-retest reliability and list equivalency of Persian quick speech in noise test in Azeri-Persian bilinguals

Background and Aim: The quick speech in noise (Q-SIN) test results have been reported to be entirely different in monolinguals compared to bilinguals. We attempted to assess the reliability and equivalency of the Persian Q-SIN test in Azeri-Persian bilinguals. Methods: The Q-SIN test was performed on 51 Persian monolinguals and 51 Azeri-Persian bilinguals by the 1st, 2nd, 3rd, and 5th lists binaurally under headphone. The signal-to-noise ratio (SNR) loss was determined for each group. The reliability was evaluated on 30 bilinguals. Results: There was no gender effect on all res-ults in both groups. The mean SNR losses of four lists were -1.19 and -0.8dB in monolinguals and bilinguals, respectively, also they were wit-hin normal limits in both groups. The mean SNR losses for all lists in monolinguals were better than those in bilinguals, but there was a significant difference between two groups for list 1 (p=0.03). No significant differences were observed between two runs for lists 1, 3, and 5 in bilinguals, and two runs for lists 1, 2, and 5 were significantly correlated. There were no significant differences between the scores of lists 2, 3, and 5 in bilinguals (p 0.000), and a moderate correlation existed between lists 2 and 3. Conclusion: The scores of lists 2, 3, and 5 in bilinguals are similar to those in monolinguals. In bilinguals, lists 1 and 5 are reliable, and lists 2 and 3 are equivalent. The overall results indi-cate limitations in both reliability and equivalency of Persian Q-SIN lists in the bilinguals.