Don't the people developing these speech/AI methods generally have advanced degrees?
In that case, shouldn't they be aware, from the same grad school training that prepared them for this work, that a (genuine) human subjects board would require informed consent for this, at the least?
I am both an Ex-Googler and a PhD researcher (working with human data). You don't require informed consent in this case, it's not human subjects research, and the terms of service cover this already. What is being done is completely legal and if people don't like it, they're free not to use the service.
because humans aren't the subject of research here, instead they are data providers. The alexa product is the subject of research here (and it's not research, it's product improvement).
I don't understand your question about terms of service and ethics here. I work with real human subjects research data and it's a completely different field that does not apply to this situation.
In that case, shouldn't they be aware, from the same grad school training that prepared them for this work, that a (genuine) human subjects board would require informed consent for this, at the least?
Do they have informed consent?