Apple has filed a patent that may contribute to the voice assistant Siri's functionality in the future. It may impart the ability to recognize different voices and attribute them to corresponding users on new versions of the software. This could give the assistant software a much-needed boost in its relevant marketplaces.
https://www.notebookcheck.net/Recent-Apple-patent-could-allow-Siri-to-recognize-multiple-different-users.324016.0.html