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.
Apperceptive agnosia
Tactile apperceptive agnosia results in the inability to shape representations specific to tactile modality. The impairment is restricted to the hands even though sensation is not impaired. This is similar to visual apperceptive agnosia in that it is a basic level of processing that is impaired. Some individuals are unable to recognize objects by touch because of a small cerebral infarction.