What are the features of hearing problem since the birth?

The hearing problem of a kid since birth

Hearing is one of the special senses for which we should be grateful to our creator. We can't enjoy our life without this blessing. But sometimes, our kids may not be lucky enough to have this important system intact. How can we identify that our kid is having a hearing problem since birth?

Developmental milestones (hearing aspect)

To understand the problem, we need to know the timetable of the development of a child, particularly the developmental milestones related to hearing. In the picture below, the illustration is quite easy to understand the important hearing-related developmental milestones in normally developed children.

Image from Illustrated Textbook of paediatric 4th Edition; page 37 

Time to notice the hearing problems

It is a normal response, even for the newborn, to startle to loud noise. If by 6 weeks, a baby doesn't startle to a loud voice or sound, it indicates that the kid may have a hearing problem. 

Turning to a voice or sound out of sight should occur in around 7 months of age. Polysyllabic babble starts at around 7 months as well. By 10 months, the kid should start a few discriminate sounds, e.g mama, dada etc. At around 1 year, a baby should understand and response his/her name. If by the age of 12 months, nothing of the above-mentioned things happens, parents should really be concerned about their baby's hearing issues. 

By 18 months, the baby should learn 6-10 words and should be able to point to 4 body parts. A baby should also be able to follow simple commands,e.g. lie, sit etc. If such things don't happen, we should think of some hearing-related problems. 

By 20-24 months, a baby should learn to make simple phrases using 2 or more words. By 2 and a half years, a baby should be able to talk constantly of 3-4 words sentences. After this period, if a baby can't make meaningful short sentences, patients should be worried about the hearing problems of their kid. 

A checklist of hearing for parents

Image from Illustrated Textbook of paediatric 4th Edition; page 42