Introduction

Audio can be rendered from the Render Menu.

Options

Relative Path
Select the file path relative to the blend-file.
Accuracy
Sample accuracy, important for animation data (the lower the value, the more accurate).
Audio Containers
See here.
Codec
Some Audio Containers also have option to choose a codec. For more information see here.
Split Channels
Each audio channel will be rendered into a separate file.

参考