There are technical reasons to use a female voice. A female voice better matches the frequency response of the human ear than a male voice, and the frequency re

There are technical reasons to use a female voice. A female voice better matches the frequency response of the human ear than a male voice, and the frequency response of small loudspeakers like those found in phones. However, a pitched-up male voice could have the same frequency content, and it wouldn't sound any weirder than this "neutral" voice.