Will a hearing problem cause my baby to have a developmental delay?

YES. Hearing is a crucial part of language development.Expressive and more important receptive language is strongly associated with learning.If your child appears to be having problems speaking , understanding speech or not responding to sounds, please have him/her seen by a doctor and or an audiologist.Long term hearing deficits could create long term sequalae.
Could be. Not only speech delay, but potentially serious emotional and social issues can occur. This can mimic autistic behavior if not recognized and corrected.Fortunately there is routine screening of all newborns in most places for congenital hearing loss, which will allow prevention of these complications.
Yes. Hearing loss is definitely associated with delayed speech, therefore all infants should have their hearing tested at birth, before they leave the hospital. If hearing loss is defected, it should be treated right away.