As time goes on, you will hear all sorts of sheep noises, and you will learn to differentiate between them primarily because of the different tones and pitches. You can learn your sheep's voices, just like you know your dog's bark or you know your mom's voice (though of course sometimes I have a hard time because my mom is a twin and she and her twin sister sound exactly alike

). After five years of owning sheep, I know the difference between a lamb crying out for it's mother, a sheep wanting some feed, a ram "seducing" a ewe, a ewe bleating to her new lambs, lambs playing with each other, and a stressed sheep. I'm sure there are more I know, I just can't think of any right now

You can also learn the expressions on a sheep's face...curiosity, annoyance, contentness, stress, etc.
ETA: Some sheep, as you will find out, have very obnoxious baas...usually they are the baas that are very "vibrate-y" or they sound like someone puking. And usually these sheep are the mouthier ones. Sheep with nice-sounding baas tend to be the quiet, more reserved sheep in the flock.

I have Montadale/Babydoll Southdown crosses and they are very quiet...I rarely hear them say anything. It's usually the lambs that make noise, but they quiet down as they mature. I did have one ewe, though, "Lily" (she's in the BYH 2012 calendar), who had a vibrate-y baa and would bleat anytime she heard or name or saw me. I'm suprised she never lost her voice because it was pretty much constant bleating with her. Whereas, my friend's sheep (she has Suffolks and Shropshires) are a mouthy bunch of sheep. I went over to her house (she keeps all hers in a barn/garage and a couple of outdoor pens) and they were sooo loud.
