My fire breather became vocal at 6 months (last April) right about the time the formal obedience started. She was always quiet and steady up to this point on marks. At a marking session, she got some really nice exciting retrieves and was totally quiet & steady. The next she was vocal at the line which continued all summer. Knowing that this is the worst possible nightmare to have, I started researching and trying different methods to eliminate the noise. After working on this all summer (very frustrating), the noise appears to be gone. What appears to have worked for me was (1) Total obedience, in the house, in the yard and in the field. I hold her and myself to a high standard. Sit, here & heel.This includes walking out the door, entering/exiting the vehicle, walking to the holding blind, etc. (2) Lots of single marks, any noise, no retrieve. I also used Lardy's method of 4-5 single marks with noise, and then one more mark with no noise. She would be vocal on the marks with noise, but however it works, she would be quiet on the last mark and I would then send her. By doing this, I was able to create an atmosphere to train in and teach her what I wanted. (3) NO TESTS. As much as I wanted to, knowing she could compete, I didn't. I was working too hard to eliminate this problem. I had also decided to let her mature some.
As she progressed and got better, I decided to take her dove hunting in September with my older dog to see where I was at in the training. If she got vocal, she wouldn't hunt the rest of the fall. Both dogs honored and were steady with no problems. Because of no calling of doves, the shots were not expected by the dogs and she wouldn't have a chance to think about the mark. Also with my numerous misses, the dogs were surrounded by excitement. Every now and then I got lucky and shot a dove and would then send one of the dogs. She whined quietly once, received a "sit" correction, then shut up and has not whined since. Even in training, she has not whined on marks. I decided to duck hunt in October with her, this time calling. Here again, plenty of noise and numerous misses, no noisefrom her. When I did get lucky, she got the retrieve. I have not had any noise since early September. What she has learned is that not every mark is hers and if she is quiet, she will get a retrieve. Now, I do not consider her fixed, as I will be running her in tests next spring. I already plan on pulling her at the line if she gets vocal, time will tell. Hope this helps.