As i say in this Purim Torah answer, we can't use smartphones because "The vaad found out that Siri's not a guy". (From the song Hang Up the Payphone by A.K.A Pella.)
However, that inspired a Siri-ous (groan) question.
According to answers to Are men allowed to listen to women on the radio?, some hold that it is forbidden to listen to women on the radio (and presumably recorded as well), due to the prohibition of "kol isha" (a man hearing a woman's voice).
But what about something like Siri, which is computer-generated female-sounding speech synthesis?
While hearing a woman simply speak is obviously permissible, it is possible to get Siri to sing by telling it "sing to me" (though the only song it knows is If I Only had a Brain, which it "sings" quite tunelessly).