It is not unusual for dying persons to experience sensory changes. Sometimes they misperceive a sound or get confused about some physical object in the room. They might hear the wind blow but think someone is crying or see the lamp in the corner and think someone is standing there. These types of misperceptions are called illusions. They are misunderstandings about something that is actually in their surroundings.
Another type of misperception is hallucination. Dying persons may hear voices that you cannot hear, see things that you cannot see, or feel things that you are unable to touch or feel.