This study explored the effects of lecture speech rate and duration on L1 Chinese listeners' listening comprehension of online L2 English lectures on free-recall and cued-recall questions. There are many factors that may affect a Chinese listener's listening comprehension of online English lectures. The current study focused specifically on the effects of speech rate and duration, and explored the possibility of identifying tools that listeners might use to control these factors during online lectures in order to achieve better learning experiences. Using an exploratory quasi-experimental approach, this study explored the research questions in three phases: 1) An initial quasi-experiment was conducted via Qualtrics and applied as a pilot study; 2) The quasi-experiment was revised, with a new link sent out to potential participants from both the United States and China; and 3) Quasi-experiment responses were collected and analyzed. Based on 28 participant responses, the findings from the current study suggest that the interaction between speech rate and duration impacted L1 Chinese listener's comprehension of online L2 English lectures. The findings also suggest that study participants' responses on various types of questions were affected differently by the speech rate and duration of the lectures. / Doctor of Philosophy / It is assumed that the slower and the shorter the listening material is, the better the foreign language learner's listening comprehension will be. Is this true? This study explored how a lecture's speech rate and duration may affect L1 Chinese listeners' listening comprehension of online L2 English lectures on free-recall and cued-recall questions. It discusses the possibility of identifying tools for listeners to control the speech rate and duration of online lectures in order to help listeners achieve better learning experiences. Using an exploratory quasi-experimental approach, this study explored the research questions in three phases: 1) An initial quasi-experiment was conducted via Qualtrics and applied as a pilot study; 2) The quasi-experiment was revised, with a new link sent out to potential participants from both the United States and China; and 3) Quasi-experiment responses were collected and analyzed. Based on 28 participant responses, the findings from the current study suggest that speech rate and duration worked together to impact L1 Chinese listeners' comprehension of online L2 English lectures. The findings also suggest that study participants' responses on various types of questions were affected differently by the speech rate and duration of the lectures.