Senegals are a companion species of parrot and this simply means that they will bond with humans better than an aviary species and because of this they require a lot of attention from their humans. They require close to 4 hours of out of cage time every day with most of this spent in close personal contact with their chosen human.
They are fairly independent as far as parrots go but they are still parrots and they are never alone in the wild from the time they are born until the time of their death and they count on the closeness of their mates and their flock for their sense of security and well being. When you brought this parrot home you became its parent, flock and eventually its mate so it depends on you to fill all of these roles in its daily life.
This calling for you is actually quite normal especially given the circumstances. There are many people that recommend that you ignore the birds screams, but I am not one of those. when your bird screams for you it is taking a big risk as in the wild this type of screaming will attract a predator looking for an easy meal. What I do for this flock calling is to always answer the bird and then as soon as the bird quietens down just a little I appear in the birds space and not only check on the bird but answer it as well. I also pick out a whistle of just one or two notes as my answer to the flock call ( if you can whistle) or a word or short phrase to use as an answer to the bird. Over time the bird will usually pick up on my answer and start using it as its flock call provided that you are consistent and keep using the same call. This allows you to choose a call that is not as loud or as nerve wracking as their natural call.
I hope that this will help you through this.