Yes, I've heard Whitetail Vocalizations many times... the thing I learned though is that they usually aren't loud.  They are usually the same volume of the birds, squirrels, etc. that you hear around you constantly when hunting.  Its entirely possible that you've heard them, and not realized that's what it was.  It's so subtle sometimes that you wonder how other deer nearby could hear it, but they do... it's like they're hearing is wired to tune into those specific sounds.  Also, that "barking" that some of you keep mentioning, is not a vocalization at all.  That's the one sound that a deer makes that is extremely loud.  It's called "blowing," and they do it by forcing air through their nostrils in a very hard manner, creating that sound.  It usually means they busted you (or some other nearby threat), most likely by smell, and they are alerting all other deer in the area to stay away.  If this happens to you often, you need to pay more attention to your Human Scent Elimination system (I use the Evade Scent Elimination System by Doc's Deer Scents), and to hunting the right wind conditions.  If you're lucky enough to have multiple stands set up, you can easily adjust to the wind conditions.  I've learned that it's often better to take a day off hunting than to go into an area when the wind is blowing in the complete wrong direction for that spot.  When I started paying attention to the wind patterns in relation to my tree-stands, I started at least having encounters with deer more than 90% of the time I hunt.  For example, if your stand is set up facing a bedding area that's to the North of you, ideally you'd want to hunt that stand when the wind is coming out of the N, NE, NW, WNW, ENE or some combination of that... you don't want to be in that stand with any S, SE, SW, WSW, ESE or combination of wind (if you can help it), as your scent would be blowing directly into the bedding are, and they're on to you before they even get up to feed for the night.  FYI, check out www.docsdeerscents.com for their full Scent Line.  

** if you want to hear how subtle a Whitetail vocalization can be, Google "deer sounds" or "deer vocalizations."