Alternatively if you're on a Mac and don't want to use audio, you can also just add a Notification Hook (/hooks)

  osascript -e 'display notification "Waiting..." with title "Claude Code"'

You can probably do the equivalent using powershell in windows, and the notify-send [1] in linux.

[1] - https://manpages.ubuntu.com/manpages/resolute/en/man1/notify...