Although most people rip and burn audio CDs that contain music, you can rip and burn any type of audio to CD, such as motivational speeches, foreign language lessons, or recordings of old radio shows.
By creating your own custom audio CDs, you could, for example, start off with your favorite song in a foreign language, follow it with a motivational speech, follow that with a 30-minute foreign language tutorial (in that same language), and end with a recording of a radio show in the foreign language you're studying. That might be a nice way to create your own immersion CD in a particular foreign language. Or try the same sort of thing for any sort of sales training or educational CD.
Custom audio CDs can also come in handy for creating your own "Greatest Hits" collection of songs from different albums. Put together your favorite list of Beatles songs or songs from the '90s and listen to your CD the next time you have to drive a long way. If you're a musician, you can paste together a CD of different playing styles so you can hear and learn from different recording artists.
The types of music or audio files you can burn on a CD are endless. With a little bit of creativity combined with your music collection, you're sure to find a way to burn custom CDs that you and others will enjoy.