Even though a person may have good listening ability, he or she may not always be able to understand what is said in every situation. In order to understand messages, some conscious action is necessary to use this ability effectively in each listening situation. This action that a listener must perform is "cognitive" or mental, so it is not possible to view it directly, but we can see the effects of this action. The underlying action for successful listening is decision-making. The listener must make these kinds of decisions: