My Google Home isn't the best at figuring out if me (or someone else) actually says "Hey Google" or "OK Google." Sometimes I'll be watching a video where no one says anything remotely similar to those phrases, and the lights on my Home flip on. But I have noticed that most of the time, the lights turn off a split-second later, as the Home actually realizes that no one called for it (presumably once the voice clip is processed by Google's servers).
Amazon appears to be giving Alexa a similar ability, with the introduction of 'Cloud-based wake word verification.' Essentially, any device with Alexa already listens for a wake word with the Wake Word Engine (WWE). But now, an additional cloud-based check verifies the phrase. If the second check thinks it was an accidental trigger, it will tell the device to close the audio stream and turn off the voice indicator.
Manufacturers will have to update their Alexa-equipped devices to use the new verification, but Amazon has tried to make the process as painless as possible. The new Ecobee4 smart themostat is the first generally-available product using this new feature.
- Amazon Developer Blog