Today, a newborn, in his crib, can be tested for hearing impairment, and if there is a problem, there are cochlear implants and therapies for children as young as newborns to learn to talk. I worked in a school in Jerusalem like this for a year and was very impressed, the children spoke with normal tone and pitch, and they changed their batteries as often and as much of a routine as I change the batteries in my flashlight.
Then there are children with constant ear infections, and fluid in their ears, which for them, can be painful. They hear as if they are underwater, or have a bad phone connection. When parents notice their child isn't babbling, or making sounds or responding to sound, they should get their hearing tested. Speech therapy will help the child, and the family, learn what the developmental milestones of speech are, and help their child, along with their teachers, get the child to a learning level commensurate with his peers. Usually children outgrow ear infections.
Hearing impairment becomes a part of your life, but it need not impair you.