When my black lab gets on a squirrel (or other animal in the woods) her ears turn off, or so it seems. I have had mixed results with bleats, grunts, whistles, "hey," etc. on stopping bucks. If they are literally chasing a hot doe I've had low success at getting them to stop. Like my lab, I think their mind is so focused on the "task at hand" that it's much harder to get them to stop. Occasionally I have had the doe finally stop to look, which stopped the buck.
But I also agree with CaptainKirk....if you are confident on moving targets with your rifle and it's a clear shot, a round ball through the vitals will stop them permanently! The buck below was on a hot doe trail and was on a fast trot nose-to-the-ground 65 yards down a steep hill from my stand. He would not stop, so I tracked him with my sights and when he hit the next opening the .530 round ball did it's work and he went down within 30 yards. The second one was actually on a hot doe. He even SAW me at about 20 yards stopping behind some brush I didn't want to shoot through, then continued after the hot doe that had run right in front of me. He wouldn't stop again as he was trying to catch up to the doe, so was taken as he quickly tried to catch up to her.