8.2 Audio

Using audio files
Earlier in the course we saw how you could use the Audacity software to record and edit your own audio files. If you want to use audio files in your course you can either create your own, perhaps a short course introduction or you may wish to use pre-recorded audio files released as Open Education Resources. You may even want to use clips from an OER audio file that you have downloaded.

To create your own audio files, you can record then directly onto your computer, or some mobile phones and mp3 players include voice recording software.

As with other multimedia, audio files can get large very quickly, so you'll need to watch out that the files you create are manageable for your users. There are several audio files types you may come across:

WAV: these are the raw (uncompressed) audio files, this is usually what be produced when you record your audio. The files sizes would usually be prohibitively large to include in your course, so you'd need to compress these files into one of the following types:

MP3: I'm sure you've all used mp3 files before, these are probably the most common type of audio file, well balanced between compression and quality.

OGG: This is an open source audio format. Similar to mp3, except that mp3 is a proprietary compression format and ogg is open source.

To give you a rough idea of files sizes and the difference compression can make, one minute of music in wav format would take up around 10Mb but in mp3 or ogg format it would only use up 1Mb.

There are many other audio file formats available, but you will need to ensure that your students have the correct software installed to be able to play these files. Mp3 would be the format which students are most familiar with and so least likely to have problems downloading and playing.