How do I politely ask my roommate to train her dog to stop barking?

Hi there. I'm 27 years old and live with an older woman who has three small dogs. One of them is incredibly energetic and enjoys barking for attention, at people walking by, and any noises.

It's really getting me worked up as the problem has only recently started when she got the puppy, and it's getting worse. How do I politely ask her to improve this as she owns the house and is renting to me?