Effects of alternative communication on the communicative effectiveness of an individual with a progressive language disorder.

This study was designed to investigate the effects of two different modes of communication on the communicative output of an individual who is no longer able to communicate verbally, presenting with a primary progressive aphasia and apraxia of speech. The two treatment approaches included training the patient with a text-to-speech alternative communication device and with American sign language. An alternating treatment design was used to compare two communicative approaches (an alternative communication device and American sign language) on the subject's communicative effectiveness.