Stereo

Stereophonic sound, also simply called stereo, is the reproduction of sound using two or more audio loudspeakers. This creates a pleasant and natural sound heard from various directions, as in natural hearing. 
The word "stereophonic" comes from Greek "stereos" = "solid" and "phōnē" = "sound". It was coined by Western Electric.
In popular usage, stereo usually means two-channel sound recording and sound reproduction using data from two speakers. The electronic device for playing back stereo sound is often called "a stereo".