Single-talker stimuli were used in:
Wiener, S., Lee, C.-Y., & Tao, L. (2019). Statistical regularities affect the perception of second language speech: Evidence from adult classroom learners of Mandarin Chinese. Language Learning, 69(3), 527-558. doi: 10.1111/lang.12342
Multi-talker stimuli were used in:
Wiener, S. & Lee, C.-Y. (2020). Multi-Talker Speech Promotes Greater Knowledge-Based Spoken Mandarin Word Recognition in First and Second Language Listeners. Frontiers in Psychology - Language Sciences. 11:214. doi: 10.3389/fpsyg.2020.00214