Why computer voices are mostly female

- CNN.com

Another answer lies in history. According to some sources, the use of female voices in navigation devices dates back to World War II, when women's voices were employed in airplane cockpits because they stood out among the male pilots. And telephone operators have traditionally been female, making people accustomed to getting assistance from a disembodied woman's voice.

When automakers were first installing automated voice prompts in cars ("your door is ajar") decades ago, their consumer research found that people overwhelmingly preferred female voices to male ones, said Tim Bajarin, a Silicon Valley analyst and president of Creative Strategies Inc.

This may explain why in almost all GPS navigation systems on the market, the default voice is female. One notable exception has been Germany, where BMW was forced to recall a female-voiced navigation system on its 5 Series cars in the late 1990s after being flooded with calls from German men saying they refused to take directions from a woman.

"Cultural stereotypes run deep," said Nass, who details the BMW episode in his book.