Are you looking to restore the Mac startup chime? Many newer Macs do away with this feature which was first introduced to Macs in 1999. Bringing it back involves the terminal, but like most simple commands they can be copy/pasted.
Bringing Back The Chime
Open the Terminal and paste this command:
sudo nvram BootAudio=%01
You’ll then have to enter your administrative password.
If you want to turn the chime off, use this command:
sudo nvram BootAudio=%00
And that’s it.