I created a new place. I renamed SoundService to Soundscape. (Soundscape is actually a SoundService, and defaults to the name SoundService in new places.) I saved to a local file, closed, then re-opened it.
I repeated the same steps with a place uploaded to ROBLOX. In neither case did any sounds get added to Soundscape.
Try disabling all plugins. If you’re willing to go as far as a reinstall of ROBLOX, that might clear out any persistent, weird bugs. If neither of those work then it’s probably a good idea to attach some OS and hardware information since this issue does not seem to exist for everyone and having an idea of what specific configurations it occurs on will narrow down the bug.