Selective Hearing

How our ears screen out sounds so that we can listen selectively only to those sounds we want to hear - like a friend's voice across a noisy room for instance - has been revealed by scientists in Australia. Gary Housley, from the University of New South Wales, has found that the inner ear, known as the cochlea, contains a population of sound-sensitive "hair cells" that communicate with the brain and work like miniature amplifiers to control the sensitivity of the ears to different sound frequencies...