Claire would like to know if there's a mechanism for her brother in law that will enable him to communicate with noises he can make. He's very limited. Leo says that Google has done a lot of work on voice recognition through its Google Assistants. But it may be very customized. Leo recommends going to the local Center for Independent Living and consult with an accessibility expert. They would know what can be done with a custom solution.
Doctor Mom says that the Amazon Echo has custom routines. But they require the activation word. Google has Action Blocks. That could help.
From the chatroom - The Brain Injury Alliance. And this might be helpful - https://spectrum.ieee.org/the-human-os/biomedical/devices/mindbeagle-brain-computer-interface-gives-a-voice-to-non-speaking-immobilized-people
Also look up Project Euphonia: it's a project from Google that is working around the issue that Claire's brother in law is facing.