<unk>  is a perceptual phenomenon that occurs when, under certain circumstances, a physical change in an auditory stimulus goes unnoticed by the listener. There is uncertainty regarding the mechanisms by which changes to auditory stimuli go undetected, though scientific research has been done to determine the levels of processing at which these consciously undetected auditory changes are actually encoded. An understanding of the mechanisms underlying<unk>  could offer insight on issues such as the completeness of our representation of the auditory environment, the limitations of the auditory perceptual system, and the relationship between the auditory system and memory. The phenomenon of<unk>  is thought to be related to the interactions between high and low level processes that produce conscious experiences of auditory soundscapes.
Change deafness
New Eyes for the Needy
Voice change
Sharsheret 
Blurred Vision
Causes of hearing loss
Far-sightedness
Eyebrow restoration