Phantom center refers to the way humanears detect the location of a sound; straight ahead, above, or behind the head. Since humans have one ear on each side of the head, sound in aforementioned locations creates an equal sensation in each ear. Thus, based only on hearing, the sound can be determined to be in one of said locations, as opposed as to the left, or to the right. In stereo mixing of sound a phantom center is often created, by the use of panning. Even though there is no center speaker, vocals could appear to come from precisely between the two speakers. In surround sound, vocals are often mapped to the center channel, eliminating the need to create a phantom center using the left and right channels.