- hearing impairment
- dyslexia
- cognitive delays
- maturation delay
- cerebral palsy
- autism
- congenital blindness
- Klinefelter syndrome
- receptive aphasia
- expressive aphasia
- apraxia (loss of coordinated movement without motor or sensory impairment)
Although there is wide variation in when children begin to communicate, the rate of language development, and the pattern of speech development, there are some key language development milestones to keep in mind. In my experience being aware of any delays or differences in your child's communication between the ages of 6 months-3 years is critical. At 3 years of age you can request a speech assessment through your local public school district and any issues can then be addressed with Early Intervention services. If there are significant challenges before age 3, you can ask your pediatrician for a referral to a developmental specialist. If your pediatrician assures you that children develop at different rates, but you are still concerned, you can continue to request a referral. Explain your concerns in more detail if necessary. Specific delays to be concerned about include: not babbling by 12 months, not understanding single commands at 1.5 years, not talking by 2 years, not using sentences by 3 years, not telling a story by 4-5 years. The challenges may also include an inability to follow directions, slow or garbled speech after age 3, difficulty putting words in the correct order (syntax), or problems with articulation (phonology).
One key issue to be aware of is the difference between receptive language and expressive language. Receptive language refers to a child's ability to understand and process the words spoken by people around them. Expressive language refers to a child's ability to initiate communication by requesting something or commenting on events around them. In normal development expressive language lags behind receptive language, thus your child should be able to understand and comply with simple one step commands (e.g. get your shoe) before they can vocalize a sentence of similar length (e.g. that's my shoe). If both domains are apparently delayed and if no hearing impairment is present a full developmental assessment should be requested.
About 60% of language delays resolve on their own. Early intervention can prevent related social, behavioral, and emotional issues. Left untreated language delays may lead to selective mutism, where social anxiety hinders a child's ability to talk with peers, large groups, and unfamiliar adults. There is no known way to prevent language delays.
To learn more about speech and language delays, you can get started here:
- Answers.com language delay - be aware this is written in a very clinical style which may be disturbing to some parents.
- American Academy of Pediatrics - I particularly like the way this page relates language delays to autism. Their list of "warning signs" of autism is more comprehensive than others I've seen, and the discussion of receptive and expressive language delays toward to bottom of the page is particularly enlightening.