Customize Beeps in OS X With Any Sounds You Want
You have a pretty good collection of different alert sounds in OS X, but if you’d rather create your own, OS X Daily walks you through the process, from recording audio to placing it in the correct directory.
The whole process is pretty straightforward. You just need to record a sound effect (or import your own) and then place it in your ~/Library/Sounds/ folder. Once the file is there, you can access it by going to System Preferences> Sound. If you’re tired of boring built-in sounds, or want to customize your alerts in more soothing tones , it’s nice to know that this is an easy process.
How To Make Your Own System Alert Sound For Max OS X | OS X Daily