Audio Notifier, developed by Lauloque, gives Blender audio notifications for success, cancel and warning events. Out of the box it notifies you of the success or cancellation of renders and baking processes. The add-on ships with default sound files under a CC0 license, with credits to IENBA.
Version 1.0.5 reduced the minimum supported Blender version to 4.2 LTS, improved notification registering to help with bugs such as #3, and added a developer mode to assist with bug reports. The add-on is compatible with Blender 4.2 LTS and newer and is released under the GNU General Public License v3.0 or later.
To install, drag and drop the file into Blender, or download it and install from disk. The extension does not require any special permissions.