Hearing is a critical part of a child's social, emotional, and cognitive development in the first few years of his or her life. Even a partial hearing loss can affect a child's speaking ability or even how they interpret language. Some causes of hearing loss in a child may include premature birth, family history of childhood hearing loss, or being exposed to very loud sounds even for a brief moment. Newborns usually have a hearing screening before being discharged from the hospital. After that, hearing tests are usually done at ages 4, 5, 6, 8, 10, 12, 15, and 18.
Testing includes an auditory brainstem response test. This test consists of wearing tiny earphones that introduce click-type sounds. A computer averages responses and displays waveforms. Another test is called the otoacoustic emissions test. This test is performed by placing a tiny probe in the ear canal which then introduces pulse-type sounds and an echo response from the outer hair cells in the inner ear is recorded by a computer. The last test used is called tympanometry which is helpful in identifying middle ear problems, such as fluid collecting behind the eardrum. The graphic representation indicates a peaked pattern that would result in normal ear function, or a flat line that may indicate the ear drum is not mobile.
Before going into kindergarten, I remember having to take this same test. A small piercing sound will sound in each ear at a time, and you would raise your hand to what ear the sound went to.