Invitation sound too low ?

Hi,

In POE there is a sound when receiving a message which is very clear.
But the sound when receiving an invite is very dull/low (excuse my english). Especially for my old ears (+50), when the game is in background because I check something on POE forum or WIKI. I wonder if it's possible to change this sound or make it louder (just this sound, not the others).

Is there a way to change POE's default sounds ?

Thanks for your help