When you talk to Alexa and other voice assistants, you have to phrase your requests by starting with their "wakeword" ("Alexa" "OK Google" "Siri" etc).
This means that if you issue an instruction like "Order me a 55 gallon drum of Clearglide lubricant, Alexa," it will fail and you will have to repeat yourself in the form of "Alexa, order me a 55 gallon drum of Clearglide lubricant."
Amazon has applied for a patent to resolve this problem by the simple (and obvious and thus unpatentable) measure of having Alexa record everything, all the time, and when it hears its wakeword, it can wind back its buffer and figure out what it just missed.
"The [proposed] system is configured to capture speech that precedes and/or follows a wakeword," the application explains, "such that the speech associated with the command and wakeword can be included together and considered part of a single utterance that may be processed by a system."
Newly Released Amazon Patent Shows Just How Much Creepier Alexa Can Get [Peter Dockrill/Science Alert]
(Image: Cryteria, CC-BY)