PURPOSE: This registered report aimed to replicate previous findings showing that years of music training predicts speech-perception-in-noise (SPIN) skills in children. In addition, it aimed to investigate whether the musician SPIN advantage is influenced by cognitive factors such as general intelligence or working memory. METHOD: Following planned sample size estimations and analyses, 62 school-age children with varying degrees of music training participated in the study. Children's general intelligence quotients, working memory, and SPIN skills were assessed during one visit to our laboratory. We implemented hierarchical multiple regression analyses to examine the study aims. RESULTS: Our regression analyses indicated that years of instrument training did not significantly account for variance in SPIN skills. The explanatory power of our model was enhanced only when working memory, particularly auditory working memory, was included as a predictor. Auditory working memory was associated with both SPIN skills and years of instrument training. CONCLUSIONS: Our study was unable to replicate previous findings that linked years of instrument training to SPIN skills in childhood. This suggests caution regarding prior claims that music training can be used with children to optimize learning in noisy environments. However, we did find evidence that musicianship is associated with enhanced auditory working memory skills, which could have positive implications for children's lifelong outcomes. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.28373786.