If loud noises send your toddler scurrying under the bed, hands over his ears, he might have abnormally sensitive hearing. Then again, he might be perfectly normal -- toddlers have more sensitive hearing than adults, so noises that might only slightly startle you can have more of an effect on little ears. Hyperacusis -- an abnormal sensitivity to sound -- can affect small children; talk to your doctor about a referral to an audiologist or otolaryngologist if you think your toddler's reactions are extreme.
Normal Toddler Sensitivity
Toddlers have better hearing and can hear higher and lower frequency sounds than adults, according to the University of Chicago. Because a toddler's ears haven't been exposed to rock concerts yet, he hasn't experienced any self-induced hearing loss. And because the world is so new to him, your kiddo hasn't learned to anticipate sounds that an adult would mentally prepare for, such as thunder after a flash of lightening or the booming of fireworks. Because he's not prepared for them, they startle him.
When to Worry
If your toddler's reaction to loud sounds is brief and doesn't trigger long-lasting tantrums, her reactions are most likely normal. But if your little gal spends most of the day with her hands over her ears, if she reacts to loud sounds by hitting her head or other forms of self-injury or if your concern over her reactions to sound is curtailing your daily activities, asking your doctor for a hearing test or an evaluation with an ear specialist is prudent.
Autism and Hearing Sensitivity
Although many parents report increased sound sensitivity in kids on the autism spectrum, studies haven't shown this to be a hearing problem specifically, but rather a problem of perception, according to January, 2011 article in "The ASHA Leader." Exaggerated responses to sound might be reinforced by parental reactions that aim to protect the child such as the use of earphones and other devices that shield the child from noise. This could exacerbate the reactions over time.
Desensitizing Little Ears
If your super sensitive little one's hearing sensitivity doesn't improve with time, you might want to consider sensory integration therapy or behavioral desensitization to help desensitize him to noises and cope with them more effectively. This method of acclimating people with hyper-sensitive hearing to loud sounds exposes them to the sound in a controlled way, starting out very softly and gradually increasing the volume. Special noise generators that produce a constant low background sound can also help. Talk to your pediatrician if you think this type of treatment would help your little guy better adapt to the often loud world around him.