Communication Aids for Disabled: Equipment that provides mentally or physically disabled persons with a means of communication. The aids include display boards, typewriters, cathode ray tubes, computers, and speech synthesizers. The output of such aids includes written words, artificial speech, language signs, Morse code, and pictures.Tape Recording: Recording of information on magnetic or punched paper tape.Patient Simulation: The use of persons coached to feign symptoms or conditions of real diseases in a life-like manner in order to teach or evaluate medical personnel.Communication: The exchange or transmission of ideas, attitudes, or beliefs between individuals or groups.Cell Communication: Any of several ways in which living cells of an organism communicate with one another, whether by direct contact between cells or by means of chemical signals carried by neurotransmitter substances, hormones, and cyclic AMP.Animal Communication: Communication between animals involving the giving off by one individual of some chemical or physical signal, that, on being received by another, influences its behavior.Communication Disorders: Disorders of verbal and nonverbal communication caused by receptive or expressive LANGUAGE DISORDERS, cognitive dysfunction (e.g., MENTAL RETARDATION), psychiatric conditions, and HEARING DISORDERS.Health Communication: The transfer of information from experts in the medical and public health fields to patients and the public. The study and use of communication strategies to inform and influence individual and community decisions that enhance health.