Holly does this too. We have real cocker conversations, hubby and me end up in fits of laughter and Holly joins in by her grumbles turning into excited woofs!.
She will come on my knee and start to grumble talk, and I grumble talk back and so it goes on.
It happens mostly when I come home from work and for all the world its like she is telling me what she has been doing all day with her Dad and I am telling her what I have been upto, it usually ends up with lots of cocker kisses laughing and excited woofing!!
I think we must be totally MAD - what did we do before we had our little Holly
Oooooooh we do LOVE HER TO BITS.