The child will perform a series of hearing tasks that will take from 1.5 to 2 hours, with a break halfway through. A routine hearing test will be given. The child will sit in a sound-treated room wearing earphones and will depress a button in response to sound or to repeat words. The words may be in quiet or mixed with noise. In a test called "immitance," air pressure change and tones will be sent through a miniature probe in the ear for about 1 minute. TEOAE (transient-evoked otoacoustic emission) testing will test the inner ear with clicking sounds. At times, noise will be presented through a probe in the opposite ear.