Sensory language is referred to as imagery in literature. Imagery is defined as
the forming of mental images, figures, or likenesses of things.
Therefore, in order to form the most realistic images, authors try to evoke and stimulate the senses of the reader (taste, touch, sight, sound, and smell). The clearest mental images are the result of the senses of the reader being stimulated so that the reader can create the most rounded image possible.
Edgar Allan Poe was a master of Gothic literature. All of his poems and stories relied upon a reader's mental images, of the setting and characters Poe described in his works, in order to heighten their senses and their fears.
For example, in Poe's short story, The Tell-Tale Heart, Poe's description of the old man's eye is bone-chilling.
One of his eyes resembled that of a vulture -- a pale blue eye with a film over it. Whenever it fell upon me my blood ran cold, and so by degrees, very gradually, I made up my mind to take the life of the old man, and thus rid myself of the eye for ever.
This description stimulates both visual and touch. Initially, one can create an image in their mind regarding the eye of the old man which resembles a vulture's eye. (Here, Poe is assuming that readers know what a vulture's eye looks like. The mental creation of this image rests on the fact that the reader has prior knowledge of the image so as to recreate it in their own mind.)
In another of Poe's stories, The Black Cat, one can easily create an image of the narrator attacking his cat based upon the description of the attack.
I took from my waistcoat-pocket a pen-knife, opened it, grasped the poor beast by the throat, and deliberately cut one of its eyes from the socket! I blush, I burn, I shudder, while I pen the damnable atrocity.
Here, one could easily "see" the narrator grasping the cat and prying out its eye. The accuracy of the mental image relies solely upon the description of the attack. While one may have never seen such an attack, one can easily picture the scene unraveling before them.
Therefore, in both accounts, the sensory language (or in literary terms, imagery) allows a reader to both connect with the text based upon the descriptions provided by the author.