A:Answer Sadly, no it does not...and, the beep is quite loud; plus, it's a series of 3 loud beeps when finished cooking.
Otherwise: this is a really nice unit, and a good value at the price. Has lots of features; and, the door opens and closes much more quietly than previous models...we like it. So: I'm considering opening it up, and putting a damper over the speaker, to mute the sound somewhat.
Haven't found a microwave, white or otherwise, in this size that allows you to turn off sound. Our previous Sharp had that feature...but, it was 17 years old; they don't make 'em like they used to.