Reaching in the dark.
Reaching for noise-making objects presented in darkness declines, then recovers, during infancy. The most probable explanation of this U-shaped function would seem to involve changes in reaching, changes in the perception of success, and changes in the body schema. There is no need to postulate any U-shaped change within the auditory system.
D000367:Age Factors; D001307:Auditory Perception; D001828:Body Image; D002657:Child Development; D003624:Darkness; D006225:Hand / Q000502:physiology; D006801:Humans; D007223:Infant; D009068:Movement; D013028:Space Perception; D014796:Visual Perception