In Behaviorism, an emitted response is a behavior or action that, when performed, acts on the organism's environment and produces different kinds of consequences that affect the organism (like reinforcement or punishment).
In his research, B.F. Skinner distinguished the difference between "emitted" responses and Pavlovian "elicited" responses that are reflexive and involuntary. An emitted response is voluntary and can be consciously stopped by an organism. An example of an emitted response would be a mouse hitting a lever in order to receive a food pellet. The mouse has done this in the past and received a food pellet, which is a positive reinforcement because it is performing an action and receiving food as consequence. The pushing of the lever is an emitted response because it is voluntary and results in a consequence of the mouse's action that affects its environment.