Any time you want to modify audio, whether it's to edit, convert, or record something, you usually need some kind of audio editing software. On the mac, a great option is Garageband. I've just starting playing with this after using Audacity for a long time (which I still recommend). Garageband makes it very easy to create podcasts with enhancements such as video and photos and chapter markers, but it might be overkill for simply trimming a sound file. For that, a good option might be QuickTime Pro. Easy Media Creator on the PC also comes with an audio editor. Some online sites offer audio editing online (which I think is amazing!). I've used Odeo with some luck, but for more powerful editing, for now I'd recommend a desktop software.

Most audio editors will open any kind of audio file. Some will allow you to convert files to other formats using via a "File--Save as" option or an "Export" option. To save an audio file in a different format, all you need to do is open it in your chosen software program and then save it in your chosen alternative format. Both Audacity and QuickTime offer several different audio options.

Recording your own audio (or having your students do so) is also easy. Both Audacity and Garageband offer recording options. Below is a screenshot of what my demo audio looked like.

The top track is a "podcast track" where you can put pictures, video, text, all kinds of things. But you don't have to put anything there. Then there are two tracks for voices and two tracks for other sounds. I recorded my voice by selecting the female voice track and clicked the red record button between the two panes. I imported a music file and trimmed it using the bottom editing pane. By clicking and dragging to select sections of the track, I was able to delete most of it. On the right is the track info where you can add effects to the track. I also faded out the music. The included help documents are easy to follow.

My suggestion is to start simple. Use a single track. Trim the beginnings and ends or cut out sections that you need. Then you can add tracks or pictures or start working with video (I'll talk about video more later.) When you're ready to save your file, you can choose file-->save or you can choose Share-->save to disk which creates an mpeg 4 file appropriate for submitting as a podcast.

Audacity is not quite as friendly-looking as Garageband, but it's just as easy to use and it works on Mac, Linux or Windows. Like Garageband, Audacity can have multiple tracks. To import music into audacity, simply choose Project-->import. From here you can edit the file, apply effects or simply save it in a different format. You can add tracks by going to Project-->New audio track. Like Garageband, too, Audacity could be used to do much more complex audio creation and editing, but it's still useful for simple edits.

Tomorrow, I'll explain how to upload these files to Blackboard, to the web, and into a blog.

technorati tags:audio, garageband, audacity, howto