That would be Majel Barrett-Roddenberry, who voiced all of the computers in all of the various Star Trek shows and films, except the most recent ones. I met her at a fan run SF convention, Con*Cept, in Montreal, and she was a really nice person. I do think that we have enough of her speaking as the computer along with her other spoken roles to have a fairly complete vocabulary for a voice assistant. I am sure many others in addition to myself would like to have this on their phone, house assistant, car, GPS, etc.
As the saying goes:
MAKE IT SO!