Hi Hiroyo, If you pull a video into Apple's iMovie, you can inset a 'cut' at each point where the audio would start or stop; then extract the audio from between those new cuts where you don't want sound and delete those audio tracks. A student could then record and insert a new audio track as appropriate, and export to QuickTime for the instructor to review. As others have suggested you could record in Audacity or other external audio recorder, but iMovie's built in recorder will work fine too. Jack Burston worked with this a few years ago and did a few presentations on it; he also scrambled the clips in the video and asked students to reorganize the video clips. Here's the link to the session that I attended: http://wlc.csumb.edu/digitalstream/2004/Abstracts/burston_abstract.htm The proceedings from that conference have not been released in digital form yet, but paper versions are available. I'm sure there are other models out there, but I don't have references. Anyone else? Gus __________________________________ "The identity of the university will be framed by substantive commitment to multilingual, multicultural, gender-equitable learning...[and] will invest in preparation for the future through integrated and experimental use of technologies as resources to people, catalysts for learning, and providers of increased access and enriched quality learning." CSUMB Vision Statement http://csumb.edu/site/x11547.xml _____ Gus Leonard, Language Laboratory Coordinator School of World Languages & Cultures * Building 48, Room119 * California State University, Monterey Bay * Email: [log in to unmask] * (831) 582-4446 * http://wlc.csumb.edu Past-President, SouthWest Association for Language Learning Technology * http://swallt.org *********************************************** LLTI is a service of IALLT, the International Association for Language Learning (http://iallt.org/), and The Consortium for Language Teaching and Learning (http://www.languageconsortium.org/). Join IALLT at http://iallt.org. Subscribe, unsubscribe, search the archives at http://listserv.dartmouth.edu/scripts/wa.exe?A0=LLTI Otmar Foelsche, LLTI-Editor ([log in to unmask]) ***********************************************