One in four hearing-impaired children are not diagnosed by age 3, according to the National Foundation for the Deaf. The reason: A lot of parents don’t know the signs of hearing loss.

“Parents should know how to detect hearing problems at various stages during their child’s development” says Paula Dimmitt, a pediatric nurse practitioner at Children’s Medical Center. The earlier a hearing problem is detected, the earlier proper treatment can be started to help the child hear and learn to talk.

The NFD, the National Institute on Deafness, and the American Speech-Language-Hearing Association offer checklists to assess a child’s hearing. If parents answer “no” to more than one or two of the examples, the child’s hearing should be checked by a trained audiologist.

Does your child:
React to sudden loud sounds by jerking or blinking; stirring while asleep; crying; increasing or decreasing sucking?
Seem soothed by your voice?
Turn his or her eyes and/or head when you speak?
Smile when spoken to?

Does your child:
Look up or turn toward a new sound or voice?
Respond to “no” and changes in tone of voice?
Imitate his or her own voice?
Enjoy rattles and other soundmaking toys?
Begin to repeat sounds (like “ooh” and “ba-ba”)?
Pay attention to music?
Seem scared by loud sounds?

Does your child:
Respond to his or her name, a ringing phone or someone’s soft voice?
Know words for common things (“cup,” “shoe”) and sayings (“bye-bye”)?
Make babbling sounds, even if alone?
Start to respond to requests, such as “come here”?
Look at things or pictures when someone talks about them?

Does your child:
Play with his or her voice, enjoying the sound and feel of it?
Point to or look at familiar objects or people when asked to do so?
Imitate simple words and sounds, and use a few single words meaningfully?
Enjoy games like peek-a-boo?

Does your child:
Follow simple directions, such as “Give me the ball,” “kiss the baby” and “bring me your shoe”?
Use words he or she has heard often?
Use two- to three-word sentences to talk about and ask for things?
Know 10 to 20 words?

Does your child:
Understand simple “yes-no” questions, such as “Are you hungry?”
Understand simple phrases,such as “in the cup,” or “on the table”?
Enjoy hearing you read to him or her?
Point to pictures when asked?

Does your child:
Understand “not now” and “no more”?
Choose things by size: big, little?
Follow simple directions, such as “get your shoes” and “drink your milk”?
Follow two requests, such as “Get the book and put it on the table”?
Understand action words?