You hook up a MEMS microphone and read the data (via I²S), encode it to mp3 and also to FFT data and stream the mp3 audio stream via UDP to a server, which can

You hook up a MEMS microphone and read the data (via I²S), encode it to mp3 and also to FFT data and stream the mp3 audio stream via UDP to a server, which can then be connected to via VLC player to play back that stream. The FFT data can also be streamed in a custom binary format, in order to have an real-time visual representation of the streamed mp3 audio.