default to custom sounds

You can use the default sounds as custom ones if you download them here https://soundcloud.com/broa-2/sets/path-of-exile-alert-sounds
Then rename the ones you use to:

1maybevaluable.mp3 for divines
2currency.mp3 for chaos
3uniques.mp3 for uniques
4maps.mp3 for <t11s
5highmaps.mp3 for red maps
6veryvaluable.mp3 for exalts

Put the sounds in C:\Users\x\Documents\My Games\Path of Exile (same directory as the filter file)