Intercept voice commands on Google Assistant or Alexa

Question

I'm planning on doing an experiment, where we will setup a Google Assistant or Alexa device and see how people would interact with voice assistants in a certain environment. It's basically a Wizard of Oz experiment (https://en.wikipedia.org/wiki/Wizard_of_Oz_experiment). Is it possible to intercept the voice commands before they get passed to the Assistant or Alexa? This could help me decide/manage if I want to handle the user input or let Google/Alexa handle it.

Answer 1

Will you be using a purchased "original" device or will you use, e.g. an Raspberry PI and build it yourself?

For the former this won't be possible out of the bow. However, I recently stumbled upon an article. It describes a new device which would achieve something that might help you: It allows you to "reprogram" the activation word for Alexa and Google Assistant. The article mentions that the device's hardware is a Raspberry PI. So, I guess you could build something similar yourself. That was also the first idea that came into my mind.

I would imagine something like this:
On your raspberry you have a script (I guess written in python would be easiest) that listens for the wake-word, e.g. "Alexa" and also records the following voice. However, you have Alexa itself not running for now, so it doesn't get triggered. Your script also includes a logic for when to pass the command on to Alexa or what to do with it instead. When it decides that the command is to be passed on, the script starts Alexa and replays the recording. Thus, triggering it the same way the users would have triggered it, in the first place.
Another idea would be to use two microphones. One for your script and one for Alexa. Your script having the ability to mute/unmute those.

Pleas take into account that those are just spontaneous ideas. It's completely possible that I've missed something and this wouldn't work. But until somebody who has done this before comes up, I'd give it a try!