Why doesn't Nikon Coolpix 4600 digital cameras movie clips feature sound.?

It's a cost driven market today. The manufacturers have to look for any and every way they can to get their costs down. The cost of the microphone, audio IC, playback speaker and amplifier makes a big difference in costs for a feature that won't get that much use.

It just doesn't. The 5600, which costs a little more, does. Maybe it's a memory issue, but I don't know.

Neither does my sister's Olympus - Yet my dad's Sony does. Generally it just depends on the model, brand and whether they could be bothered to put a microphone in it. I've noticed, most of all, the cameras who do a better video have sound, while those ones that do not really that great video don't. It's not a standard feature of the stills camera, after all.