Since we don't know which sounds you're fond of and which you are not, go to the sound folder, look for the sounds you don't like and delete the lines in the script (script.rpy) or replace the sound files with something else.
With a text editor like notepad++, all you need to do is bookmark the lines (e.g. play sound "sound/jump2.ogg") and delete them
Example: jump2.ogg in script.rpy
ctrl-f jump2.ogg gives you the line "play sound "sound/jump2.ogg".
In the same window, the tab mark gives you the option to mark all the lines (play sound "sound/jump2.ogg). Checking (√) Bookmark line adds a blue dot at the beginning of each line.
Close the search window and delete all the bookmarked lines via Search → Bookmark → Remove Bookmarked Lines.