Incorporating Sound files into Your Moodle Course
As with video files, you can upload sound files to your course. Sound files may be useful for a number of teaching activities, such as translations (for a language course in which students are translating content) or pronunciation practice (for an ESL or a foreign language courses). You can also upload recordings of historic speeches, poetry recitation, and music (for interpretation or theory courses). No doubt you can find all kinds of uses for sound files.
The MP3 format is the sound file most compatible with Moodle. You can use any number of different conversion tools (which are usually bundled with newer computers) to create MP3 sound files. The following sound file formats are widely used:
- .mp3 mp
- .aac
- .wma (Windows Media Audio)
- .ra (Real Media)
A good program for creating and converting sound files is Audacity(http://audacity.sourceforge.net), a free, open source software for recording and editing sounds. It's available for most operating systems (Mac OS X, Microsoft Windows, GNU/Linux, and others). With Audacity, you can record your own lectures, readings, or music and then optimize those files for Moodle and save them in an MP3 format. Audacity also enables you to open other sound file formats and play with them and save them as MP3 files, or you can open an audio file in another format.
Audacity enables you to
- Record live audio.
- Convert tapes and records into digital recordings
- Edit Ogg Vorbis, MP3, WAV, or AIFF sound files.
- Cut, copy, splice, or mix sounds together.
- Change the speed or pitch of a recording.
You can see a complete list of features at the Audacity Web site. For Audacity tutorials, visit
http://wiki.audacityteam.org/index.php?title=Tutorials
Moodle media filters use Flash to play back audio in the browser. Flash is a bit funny with audio; it requires fairly specific format ensuring that it's widely compatible with other players for iPods and cross platforms. Here are some settings to keep in mind when using software such as Audacity to create sound files for Moodle. For MP3 formats, use the following:
- A sample rate of 11.025, 22.05 or 44.1 kHz
- Constant Bit Rate (CBR) rather than Variable Bit Rate (VBR)
- Joint-Stereo rather than Mono or Full Stereo
Sample rate or frequency, measured in kiloHertz (kHz), is not the same as bit rate, measured in kilobits per second (Kbps). The latter is a measure of file size and download time and also a rough measure of quality. Somewhere between 32 and 96 Kbps is appropriate with diminishing returns beyond 128 Kbps.