Even very early in life babies can hear a wide variety of sounds. Infants will turn towards the sound of a toy and begin to reach towards it. This ability to recognise the direction that a sound is coming from improves greatly during the first few years of life. Young infants listen longer to the sound of human voice and seem to prefer it to any other sound. They are especially aware of the sound of language and like to be spoken to slowly and with a high pitch. This is sometimes referred to as ‘infant directed speech’ or even ‘baby talk’. Young babies are quite sensitive in their auditory abilities and can perceive all the categorical sound distinctions in world languages. As babies develop their auditory abilities narrow so that eventually babies are only sensitive to those sound categories specific to their native language.