The purposes of this study were to investigate the degree to which Japanese high school students acquire vocabulary from listening, what kind of explanation better promotes vocabulary acquisition, whether vocabulary acquisition through listening varies according to the participants’ learning channel preferences, and what factors best predict vocabulary that is acquired through listening. The participants, 116 second-year Japanese high school students, were taught 45 vocabulary items embedded in nine listening passages. In the control condition, no vocabulary explanation was given. In the first treatment condition, the students were provided with a spoken Japanese translation for each target word. In the second treatment condition, the students were provided with a spoken English definition of each target word.

Approximately 30 minutes after each listening session, an Immediate Recognition Posttest and a Multiple-choice Posttest were administered. Exactly the same tests were administered as Delayed Recognition and Multiple-choice Posttests 2 weeks after the instruction. Repeated-measures ANOVAs using the listening conditions as the independent variables and the results from the two tests as dependent variables showed that there was a statistically significant difference between the three conditions on the Immediate and Delayed Recognition Posttests. The L1 translation condition was more effective than the L2 definition condition, and the control condition was the least effective. However, for the Immediate and Delayed Multiple-choice Posttests, there was no statistically significant difference between the L1 and L2 conditions. Two three-way ANOVAs using the learning channel subgroups, time, and the listening conditions as independent variables, and the results from the Immediate and Delayed Recognition and Multiple-choice Posttests as dependent variables showed that there were no statistically significant differences among the three learning channel subgroups. However, the auditory learners retained more in the L2 definition condition than the visual and haptic learning channel groups. The final major analysis, a hierarchical multiple regression, indicated that passage comprehension, vocabulary size, and grammatical competence were statistically significant predictors of vocabulary acquisition through listening.