How to Change Sound for Email Notification

Well the search turned up no results. Wanted to use what is on my computer because I know the files are safe but I’m not going to be able to do that. Do you happen to know a site where it is safe to download wav files? I need a file that I can locate for this to work and I’m lost without a location I can easily access. If not I will learn to live with the default depressing sound. Or turn it off completely. Can’t imagine why it was chosen for the arrival of emails.

Again, you have been really helpful and I appreciate it. Thank you.