How do I enhance background noise in an audio file so that I might hear it more clearly?

[Tender Heart]

I have an audio wave file that my daughter recorded and sent to me from her cell phone. In it you can hear my mother abusing my children. My problem is that the sound is also distorted by the sound of a dog barking, the sound of a tv, and a humming sound. I need to clean this file up so i can use it in court. does anyone have any idea how i can remove these noises which are in the forefront of the recording, and at the same time enhance the background noise of my mother cursing and hitting my son while he is crying? (before anyone jumps on me...yes CPS and law enforcement have been called and have been as useless as ever)

thank you in advance