IBM's acquisition of Cognea, a startup that creates virtual assistants of multiple personalities, further reinforces that voice is not enough for artificial intelligence. You need personality.
I for one cheer IBM's investment, because to be honest, IBM Watson's Jeopardy voice was a bit creepy. What has made Apple's Siri intriguing and personable, even if not always an effective capability, is the sultry sound of her voice and at times the hilarity of Siri's responses. However, if you were like me and changed from the female to male voice because you were curious, the personality of male Siri was disturbing (the first time I heard it I jumped). Personality is what you relate to.
The impression of intelligence is a factor of what is said and how it is delivered. Think about how accents influence our perception of people. It is why news media personalities work hard to refine and master a Mid-west accent. And, how one presents themselves in professional situations says a lot about whether you can trust their judgment. As much as I love my home town of Boston, our native accent and sometimes cold personalities have much to be desired by the rest of the country. And we have Harvard and MIT! Oh so smart maybe, but some feel we are not always easy to connect with.