Listening is a critical element in the competent language performance of adult second language learners. Listening is a demanding process, because of both the process itself and factors that characterize the listener, speaker, message content, and any accompanying visual support. The speaker's use of colloquial language and reduced forms, familiarity of content, and ability to interpret visual supports also affect comprehension. Although once labeled a passive skill, listening is an active process of selecting and interpreting information, with several basic processes at work, each influencing teaching techniques and activities. Two cognitive processes, bottom-up and top-down, are also occurring. Research suggests a silent or pre-speaking period is beneficial for beginning language learners, allowing storage of information. Knowledge about the listening process and factors that affect it can guide listening skill development in English-as-a-Second-Language classes. Listening lessons should guide the learner through three stages: pre-listening; listening task; and post- listening activity. Numerous activities can develop listening skills: doing (physical); choosing; transferring; answering; condensing; extending; duplicating; modeling; and conversing. Teachers can incorporate activities in a way that reflects real-world integration of listening, speaking, reading, and writing. Contains 16 references. (MSE) (Adjunct ERIC Clearinghouse on Literacy Education)