It wasn’t a huge surprise to see the components in iFixit’s teardown of the Google Home. There was already a guess that the Home had two microphones and a touch interface. The device is actually fairly simple compared to similar voice interactive devices.
Here’s an interpretation of the components:
Two microphones. It’s possible to give some directionality and apply “blind source separation” algorithms with two mics. You’ll get two potential directions of arrival that are mirrored. Perhaps Google could do some sine sweeps to be able to calibrate the mics so that it can have a better sense of where a potential signal could come from.
Cortex M0+. If the DSP code is very refined, it could potentially run here. I could imagine that Google might have special speech models setup for interaction with the Google Home. It could also be that this chip handles the capacitive touch capabilities.
ARM A7 Processor. It’s more likely that both the DSP code/audio conditioning and the local wake word are running here. All of the speech clients are also likely running here.
Sound output quality would be based on the physical size of the speakers but it’s totally possible for this device to be miniaturized similar to the Echo Dot.