In classical conditioning an emitted response is a behavior or action that is a result of a stimulus that is not voluntary. Essentially a reflex, organisms cannot consciously stop these elicited responses from occurring. A Pavlovian example of this would be a dog's salivation at the sight of food. This is an involuntary response that the dogs have no control over. B.F. Skinner distinguished between reflexive elicited responses and emitted responses which are behaviors that, when performed, acts on the organism's environment and produces consequences that affect the organism such as reinforcement or punishment.
An example of an emitted response would be a mouse hitting a lever in order to receive a food pellet. This is an emitted response because it is voluntary and results in a consequence of the mouse's action that affects its environment.