A New Speech-in-Noise Test for Measuring Informational Masking in Speech Perception Among Elderly Listeners

Introduction Elderly listeners have reported concerns about speech perception in noisy environments. This partly occurs because of their increased informational masking (IM). This study aimed to develop a Persian coordinate response measure (CRM) corpus and a novel speech-in-noise test for measuring IM. Material and methods A cross-sectional validation study was conducted in two parts. Part one was the determination of the validity and reliability of the Persian CRM corpus. Part two consisted of measuring the IM at five signal-to-noise ratio (SNR; -6,-3, 0, +3, and +6) in two conditions: one with the target and masker speaker of the same sex and one with the target and masker speaker of different sexes. In each condition, the IM measurements were performed at a 45° separation angle of target and maskers and as a co-location of the speakers. A group of young listeners aged 20 to 40 years and a group of elderly listeners aged 60 to 75 years were recruited (50 study participants in part one and 47 in part two). The study was conducted from July 2018 to March 2019 at the Iran University Medical Sciences audiology clinic. Content validity ratio, content validity index, impact score, Spearman's test, and Mann-Whitney's test were used for statistical analysis. Results The Persian CRM corpus showed acceptable validity and reliability in each group (p < 0.001). The results suggested that in both azimuth locations and at SNRs of 0, -3, and -6, the IM amount in the elderly group was significantly higher (p < 0.003) than in the young group at conditions of target and masker speakers of opposite-sex. However, in cases where both target and masker speakers were of the same sex, a significant difference was observed at an SNR of 0 in angular separation and SNRs of +3 and 0 at co-located situations (p < 0.001). Conclusion A validated Persian CRM corpus has been collected for use in IM measurement studies. Overall, the IM of elderly listeners was higher than younger listeners in low-cue situations such as lower SNR. Therefore, a novel speech-in-noise test for measuring IM was validated to use in speech perception studies in the elderly population.