and assign the correct characteristics to these sources simultaneously. As soon as the auditory system has localized a sound source, it can extract the signals of this sound source out of a mixture of interfering sound sources. However, much of this binaural benefit can be attributed to two other processes, better-ear listening and binaural unmasking. Better-ear listening is the process of exploiting the better of the two signal-to-noise ratios available at the ears. Binaural unmasking is a process that involves a combination of information from the two ears in order to extract signals from noise. Early work In the early 1950s much of the early attention research can be traced to problems faced by air traffic controllers. At that time, controllers received messages from pilots over loudspeakers in the control tower. Hearing the intermixed voices of many pilots over a single loudspeaker made the controller's task very difficult. The effect was first defined and named "the cocktail party problem" by Colin Cherry in 1953. Cherry conducted attention experiments in which participants listened to two different messages from a single loudspeaker at the same time and tried to separate them; this was later termed a dichotic listening task. His work reveals that the ability to separate sounds from background noise is affected by many variables, such as the sex of the speaker, the direction from which the sound is coming, the pitch, and the rate of speech. Cherry developed the shadowing task in order to further study how people selectively attend to one message amid other voices and noises. In a shadowing task participants wear a special headset that presents a different message to each ear. The participant is asked to repeat aloud the message (called shadowing) that is heard in a specified ear (called a channel). Cherry found that participants were able to detect their name from the unattended channel, the channel they were not shadowing. Later research using Cherry's shadowing task was done by Neville Moray in 1959. He was able to conclude that almost none of the rejected message is able to penetrate the block set up, except subjectively "important" messages. More recent work Selective attention shows up across all ages. Starting with infancy, babies begin to turn their heads toward a sound that is familiar to them, such as their parents' voices. This shows that infants selectively attend to specific stimuli in their environment. Furthermore, reviews of