Definition

• In medical terms, binaural refers to perceiving sound with two ears. In technical terms, binaural refers to transmission of sound from two sources, varying in pitch or tone, to produce a stereophonic effect.
  
  

Depth Perception

• The brain's ability to process and interpret binaural cues enables it to resolve the two channels of incoming sounds into a three-dimensional "map," enabling individuals to perceive depth, distance and direction. Many theories of how binaural interaction is translated by the brain into depth and distance have been proposed since the early 20th century, but new data continue to challenge these theories. One of the most common discussions of binaural interaction concerns the accurate reproduction of sonic depth for the hearing challenged and for use in home theater surround sound systems.
  
  

Surround Sound

• Understanding binaural interactions is important to producing effective surround sound systems. "A deep understanding of the human binaural system is necessary to avoid spatial, loudness or timbral discrepancies," states J. Robert Stuart in a paper titled "The Psychoacoustics of Multichannel Audio." Some of the technical challenges posed by binaural interaction include lower hearing threshold with two ears, sub mono-threshold interpolation, binaural masking and release, binaural masking-level differences, binaural beats (interaction between separate sounds in different ears), and subliminal perception.