The concept of The Call is but an extension of concepts humans are familiar with. One goes to the porch to call the family into dinner. One picks up the phone to call another in order to converse. When giving The Call to aliens, humans are issuing a request for contact, without a voice, without words, but the meaning is sent and understood nonetheless, by telepathic and other such wordless and wireless means. The Call is made, received, and understood, and a conference is subsequently arranged. There are times of loneliness, despair, wrenching concern for a loved one injured or in trouble, times the individual wants to offer themselves in the loved one's stead, times when the path to follow is not clear and there is indecision and hesitation at the gateway, times when another is viewed as a blockage to be removed by physical and potentially violent and harmful means - these sorts of times occur, not daily, but many times in a lifetime. These are times of The Call.
The individual is in control of alien interactions affecting him or her self. This is in fact intuitively understood by most humans, even those who are unaware of alien influences over their lives. The reason this is intuitively understood is because of interactions not consciously remembered. All humans give The Call, and do so frequently during any given lifetime.