They showed a video at the end of their broadcast last night comparing what the raw microphone hears and what comes out of the XMOS chip and you can hear a much clearer voice all the time even when there is noise or you are far away from the device. It is also used to cancel out the music if you are using it's speaker output. I don't think it's doing any voice processing but it's cleaning up the audio a lot which makes the job of the wake word processor and the speach to text a lot easier. Up until now this was missing from a lot of the home made voice assistance and I think why Alexa can understand you from the next room but my home made one struggles with all but quiet conditions.