This study followed up Wang, Shu, Zhang, Liu, and Zhang [(2013). J. Acoust. Soc. Am. 34(1), EL91-EL97] to investigate factors influencing older listeners' Mandarin speech recognition in quiet vs single-talker interference. Listening condition significantly interacted with F0 contours but not with semantic context, revealing that natural F0 contours provided benefit in the interference condition whereas semantic context contributed similarly to both conditions. Furthermore, the significant interaction between semantic context and F0 contours demonstrated the importance of semantic context when F0 was flattened. Together, findings from the two studies indicate that aging differentially affects tonal language speakers' dependence on F0 contours and semantic context for speech perception in suboptimal conditions.