Macbook sometimes plays a single beep

A single loud beep from your MacBook could be due to several reasons, but it is not a standard indicator for macOS updates.

Here are some potential causes and how to stop them:

• A single beep on startup often means there's an issue with the RAM. However, since you hear it occasionally while the Mac is running, this is unlikely to be the cause. However, to rule an issue with RAM, you should run Apple Diagnostics.
• As I mentioned, macOS does not use a beep to notify you of updates, but if an update is pending, a banner or alert might be the source of the sound. You can disable getting these notifications by going to: System Settings > General > Software Update, and then, turn off Automatic Updates if enabled.
• If your Mac briefly loses power, it may play a single chime. Check for loose power connections, or try using a different power adapter.
• If you use VoiceOver or other accessibility features, some alerts can play a loud beep. Check System Settings > Accessibility > Audio and turn off Sound Alerts.
• Some third-party apps may trigger a system beep when certain actions fail. Check System Settings > Notifications for any apps sending alerts.

If none of the above helps, try booting into Safe Mode and see if the beep still happens. If it doesn’t, a third-party app might be causing it. If it does, then the next step would be to contact Apple Support directly for further assistance with this issue.

It could help us, if you can identify when your MacBook plays this beep.

That is, does it happen:

• When first starting up?
• After you log in?
• When you open/run any specific app?
• When performing some other action?
• Randomly?