Hearing Impairment: Some parents report that their child does not respond to their calling or that the child does not seem to be able to reproduce the words correctly. Children learn words by hearing them. All human beings learns to speak correctly when they hear the words being spoken by others. If a child has difficulty in hearing spoken words, then the child cannot reproduce the sound. Hearing impairment can be corrected by treatment or by the aid of external devices like hearing aids or cochlear implants.