Since the introduction of communicative language teaching, many listening materials have focused on the development of top-down listening skills, even though many ESL learners still have difficulty with bottom-up processing. Many of the standard listening materials deal with bottom-up phenomena such as assimilation, deletion, and insertion only for function words; there are no listening materials designed exclusively to train students to listen to content words, though many have variable pronunciations (e.g., restaurant > restaurant, suppose > suppose). This paper discusses prototypical mishearings of content words by Chinese (Cantonese and Mandarin), Korean, and Vietnamese speakers of English (n=18), based on the students’ written summaries of a university lecture and their subsequent performance on dictations of the segments that had given them difficulty in writing the summaries. All the mishearings were classified into four categories: (a) the phonological level, (b) the lexical level, (c) the syntactic level, and (d) the schematic level. Moreover, the hearing errors made at the phonological level were subdivided into substitutions, insertions, deletions, misperception of stress, and missegmentation. The paper also discusses what types of mishearings are most common in ESL learners’ listening and whether or not the frequency of each category above varies according to different first language backgrounds. Finally, this study addresses the pedagogical implications of the actual mishearing data from these ESL learners for listening instruction, arguing that ESL/EFL teachers should attend more systematically to bottom-up listening skills to help their learners more accurately process content words.