I have 2 purebred Yorkies, a Yorkie/Poo and a mini-dachshund. I have always had small dogs. The Yorkie/poo has a higher pitched bark. And he hears everything! But he is also my youngest. Very much still a puppy. He is almost 9 months old. He plays very well with my female yorkie who is almost 16 months old. Rocky(my other Yorkie, pictured) is 5 years old. He is much quieter. Then I have Candy, who is a mini-dachshund. She is 9 years old. I think the others keep her young. Years ago I rescued a long haired Chuauhua, she was abused. She was a purebred, and was one of the best dogs I have ever had. She was not only a beautiful dog, but very good natured, quiet, and very loving, to me. Now I am into my Yorkies, and my mini-dachshund. Hope this helps. Darlene