How do you add new sounds as warnings

[Sugar Ray]

I have new warning sounds I would like to use instead of the bells and horns.
When I look in the sound folder i don't see any thing, but on my GPS I can see them? Can I use mp3 sounds for warnings.
Thanks

 

[digital-flex]

I don't think you can use MP3, you have to convert them to OGG in order to select them when choosing a warning for your POI.