Willingness to communicate (WTC) in a target language is considered a critical variable impacting engagement when students learn the language. Notwithstanding the research conducted on WTC of students, fewer attempts have been made to investigate their willingness to listen (WTL), especially WTL augmentation. To address this gap, this research explored the impact of a long-term listening course on preservice teachers' WTL in English and identifies underlying factors influencing their WTL. To this end, a mixed-methods research design consisting of pretest, post-test and interviews was adopted. Quantitative data were collected from 45 students with a 19-item WTL scale and qualitatively from 10 students through semi-structured interviews. Quantitative data were subjected to descriptive (means and standard deviations) and inferential (Mann-Whitney "U"-test and Wilcoxon signed-rank test) statistics, while qualitative data were analysed through qualitative content analysis. Results indicated that the long-term listening course was inadequate to improve preservice teachers' WTL significantly and pointed to various individual, speaker, listener and skill variables that influenced participants' existing and increasing levels of WTL in English. These results are beneficial to English practitioners when designing practical activities and courses to enhance English listening skills, especially when communicating with interlocutors from diverse linguacultural backgrounds amid today's English diversity.