To be honest, I wouldnt be surprised if the anatomy of a dog isn't to disimilar to that of humans, so standing next to weapons fire wont be a healthy activity for the dog.
That said, I would be very interested to see your invention for dog-defenders
Like a midget at a urinal, Fred had to keep on his toes...

Aren't the dogs supposed to sit behind the guns? I know that when my ex used to shoot he either had the dogs that far in front they weren't affected by the gun, or behind him, depending on who was working. I've only ever been on one shoot, and I was beating and was so kn*ckered that I didn't notice
Life is not a bed of roses but a comedy of errors
To answer your question, My old 12 year old golden was used as a picking up dog, standing well back from the guns, he is as deaf as a post. I have 2 ess's who are 8 and 6, the 8 year old is also going deaf and I can see the 6 year old is going that way too. If we shoot with no ear protection our hearing diminishes also. None of mine stand in direct line with the guns but way back and that is still loud, their hearing is far smore sensitive than ours. Ear defenders would be a good idea but unfortunately a dog that is trained would not be able to hear whistle commands.
A Golden is born half trained, a springer dies half trained. Where are my running shoes ???