Simply stated, a factor in human hearing where delay has a much bigger effect on human perception of direction than level does
If sounds arrive from several sources, the ears and brain will identify only the nearest In other words, if our ears receive similar sounds coming from various sources, the brain will latch onto the sound that arrives first If the time difference is up to 50 milliseconds, the early arrival sound can dominate the later arrival sound, even if the later arrival is as much as 10 dB louder The discovery of this effect is attributed to Halmut Haas in 1949