Expand sound options to allow different audio files

[tqfipe]

Hi, I made a small enhancement to allow a selection of different sounds as I found the original a bit sharp. This idea has also been floated previously This could also be expanded to allow the user to insert a url to a file with whatever sound they would like for even more customisation. Finally, the soundfiles uses are retrieved from freesounds.org under CC0 license https://freesound.org/people/soneproject/sounds/244356/ https://freesound.org/people/craigscottuk/sounds/644963/