You can find the audio browser under the Audio icon in the lower left section of the expanded hand menu.

The audio browser tabs are consistent with the characters, sets, and props menus, with a tab for the audio files you've added to your project, shared categories including music, sound effects and voices, and your imported audio files.

Press Play to hear an audio file.

Use the dropdown menu to add the audio to your project or to the audio controller.

Audio that is played through either the audio browser or audio controller while recording will automatically play back the same when you watch the recording.

Next: Using the audio controller