The author of the sounds is an anonymous source and cannot be exactly pinpointed, but at least that can be aknowledged. Strelok
This is a sound pack that replaces around 80% of menu sounds and a few in battle ones too. I will be updating this too to include more sound replacements based on suggestions and what I feel needs to be added.
Its been the same for everyone who modded the menu sfx. The sounds start to lag and eventually stop working properly. The SFX are awesome but if there is a probable fix to the lag, I would consider keeping this.