Cannot import my own sound

On the countdown tutorial I did the activity where I code the buzzer to happen after the countdown. I am not trying to replicate that on my own but using a different sound. In that activity it says that the WAV file was already imported there so python can access it. But it shows no way on how to import a WAV file for python to use it. Does anyone know how to import a audio file so I can use it in code and it comes out of the pi-top-4?