The constant sound of the water prevents the bird from being disturbed by other sounds, plus it is very relaxing. You will need to protect your hand and get the hawk to perch on it. I have used gloves, towels and shirts. A t-shirt wrapped around the hand makes for fair protection, the bird has a good grip and the shirt is light. It allows you to feel what he is doing.
All birds seek higher ground.
To get the bird on, take your protected hand and push against his feet. This will trigger KILL mode, so expect a quick hard pop. Typically, the bird will strike, hold, sense this is higher ground and then calmly climb up. If the bird still refuses to get on, try pushing on the back of the legs. The bird will get scared of falling and will sometimes back step and back step onto your fist.