The emUSB-Host AUDIO class enables the communication with any device that complies with the USB Device Class Definition for Audio Devices as specified by the USB Implementers Forum.
The USB class protocol for AUDIO was defined for devices or functions embedded in composite devices that are used to manipulate audio, voice, and sound-related functionality. This includes both audio data and the functionality that is used to directly control the audio environment, such as Volume and Tone Control.
SEGGER provides multiple examples with the Audio class for emUSB-Host. One of the examples plays a voice to a connected USB speaker. If additionally an USB memory stick with a ".wav" file is connected, the audio file is played.
Another example reads audio data from an input device (like a microphone) and outputs the volume level.