From O’Regan, J. K., & Noë, A. (2002). A sensorimotor account of vision and visual consciousness. Behavioral and Brain Sciences, 24(05), 939-973:

Particularly interesting is the work being done by Lenay (1997), using an extreme simplification of the echolocation device, in which a blind or blindfolded person has a single photoelectric sensor attached to his or her forefinger, and can scan a simple environment (e.g., consisting of several isolated light sources) by pointing. Every time the photophotosensor points directly at a light source, the subject hears a beep or feels a vibration. Depending on whether the finger is moved laterally, or in an arc, the subject establishes different types of sensorimotor contingencies: lateral movement allows information about direction to be obtained, movement in an arc centered on the object gives information about depth. Note several interesting facts. First, users of such a device rapidly say that they do not notice vibrations on their skin or hear sounds, rather they “sense” the presence of objects outside of them. Note also that at a given moment during exploration of the environment, subjects may be receiving no beep or vibration whatsoever, and yet “feel” the presence of an object before them. In other words, the experience of perception derives from the potential to obtain changes in sensation, not from the sensations themselves. Note also that the exact nature or body location of the stimulation (beep or vibration) has no bearing on perception of the stimulus – the vibration can be applied on the finger or anywhere else on the body. This again shows that what is important is the sensorimotor invariance structure of the changes in sensation, not the sensation itself.

Lenay, C. (1997) Le mouvement des boucles sensori-motrices aux représentations cognitives et langagières. Paper presented at the Sixième Ecole d’Eté de l’Association pour la Recherche Cognitive.