Concern should begin when it is recognized the child is falling below the key milestones. It is important to allow for individual differences when evaluating a child's speech. If parents have concerns about their child's speech development, they should seek professional help for an evaluation. A good speech clinic can soon tell you if hearing needs to be checked, and can give guidance as to how best to help the child. Another good source of help is the local school district, where evaluation and therapy services are usually available.
Many districts offer programs for preschool children and some even extend their services to infants.
Your input and comments on how to enhance our effort are welcomed and appreciated.