If you’re like me, you don’t love it when your Mac makes that sign-in sound every time you open the lid. (Assuming you use iMessage/Messages for any IM services.) Here’s how to disable it. (And only it.)
- Make sure Messages is closed.
- Go to your Applications folder.
- Find Messages.app and right-click it. Choose Show Package Contents.
- Find the Resources folder.
- Look for a file called Logged In.aiff.
- Delete that mess.
Next time you open it, that sound will be gone. (Note: This may not work on El Capitan.)