List equivalency and critical differences of a mandarin Bamford-Kowal-Bench sentence in babble noise test for adults and preschool children with normal hearing

Purpose: The purpose of this study was to determine the speech recognition equivalence of Mandarin Bamford-Kowal-Bench (BKB) sentence lists with adults and children with normal hearing. 

Method: A total of 32 lists, each of nine sentences, were compiled from a cor-pus of BKB-like sentences with paired babble in Mandarin. Interlist equivalence, critical differences, and sensitivity of performance to signal-to-noise ratio (SNR) were examined. Experiment 1 included 64 native Mandarin-speaking adults with normal hearing. Experiment 2 included 54 native Mandarin-speaking children with normal hearing aged 4–6 years. 

Results: Among the 32 sentence lists, 28 lists were confirmed to be equivalent in adults, with a mean SNR required for 50% correct (SNR₅₀)of −5.9 ± 0.1 dB, a mean slope of 22.3%/dB ± 1.5%/dB, and a grand 95% critical difference sub-sequently calculated as 27.2% for score. From the 28 equivalent lists, 27 lists were selected and observed to be equivalent in children, with a mean SNR₅₀ threshold of −2.0 ± 0.2 dB, a mean slope of 15.8%/dB ± 1.1%/dB, and a grand 95% critical difference of 24.6% for score. 

Conclusions: The Mandarin BKB sentences in babble noise test offers an opportunity for clinicians and researchers to assess speech understanding in adults and preschool children in an efficient manner. For comparisons of perfor-mance in different test conditions, 28 equivalent lists are available for adults and 27 equivalent lists for preschool children. The 95% critical difference values can be used for total percentage correct or SNR for 50% performance. Future work will examine the clinical utility for school-age children and children who are deaf and hard of hearing.

Supplemental Material: https://doi.org/10.23641/asha.24400066 Copyright © 2023 American Speech-Language-Hearing Association.