More than four decades after the sexual revolution, the word “vibrator” still has the power to elicit blushes, discomfort, snickering. And yet, according to the first academic, peer-reviewed studies of vibrator use, it is nearly as common an appliance in American households as the drip coffee maker or toaster oven.

Fifty-three percent of women and nearly half of all men report having used a vibrator, according to two new national surveys from Indiana University recently published in The Journal of Sexual Medicine...