Rules regarding editing SFX for game session unload use

Hi. I’ve been a loyal and grateful user of Syrinscape for over a year now and I want to say thank you for all the possibilities it gives me, as I am using the Theatre of the Mind-playstyle a lot. There are some concerns though and I want to ask you directly regarding me wanting to edit some monster sounds to make them more screachy,… making a zombie-growl more feline for instance or make a neutral sounding scream sound more highpitched and combined with other growly stuff. Am I allowed to do that as long as I keep respecting the general rules for using Syrinscape officially (like posting game sessions online), giving shoutouts and use the sound-effects properly?
Again thank you for the awesomeness