I know no one these days use FTP transfer but I still do. And this is something I am really annoyed at during transfers.
So if you are one of those people who want to get rid of this follow this.
On Windows 8 and above
- Open Notifications and Settings by pressing the windows key.
- Scroll down to Filezilla.
- Click on it. Don't turn it off from there directly.
- Inside it you will find an option to turn off the sounds.