Speech perception
Agnosia is "the loss or diminution of the ability to recognize familiar objects or stimuli usually as a result of brain damage". There are several different kinds of agnosia that affect every one of our senses, but the two most common related to speech are speech agnosia and phonagnosia.
Altered state of consciousness
Cannabis is a psychoactive drug that is known to alter the state of consciousness. Cannabis alters mental activity, memory, and pain perception. One who is under the influence of cannabis may (or may not) experience degrees of paranoia, increased sensitivity, and delayed reactions not normal for their usual conscious state. A 2009 review of anxiety and cannabis studies concluded that “frequent cannabis users appear to have higher levels of anxiety than non-users,” and that “a considerable number of subjects developed anxiety disorders before the first symptoms of cannabis dependence.” That led researchers to believe that anxiety-prone people tend to use cannabis as a self-prescribed anxiety medicine, opposing the idea that cannabis is what's causing the anxiety. (Frazier, 2010)