It is important to know the difference between an articulation disorder and a phonological disorder.  An articulation error is specific to a particular speech sound. A phonological disorder is a simplification of the sound system that results in patterned speech sound errors.

An articulation disorder refers to problems making sounds. Young children often make speech errors. For example, some children have difficulty making the “r” sound and substitute this sound with a “w” (e.g saying “wabbit” for “rabbit). Speech sounds can be substituted, changed, added, or deleted.

A phonological disorder involves patterns of sound errors.  For example, a sound produced in the front of the mouth like “t” and “d” is substituted for a sound produced in the back of the mouth like “k” and “g” (e.g. saying “tat” for “cat” or “do” for “go”).  Many phonological process errors are common and appropriate but at a certain age are no longer expected.

The cause of some articulation and phonological disorders is known; however, in most children we do not know.  A number of studies have identified the following risk factors (Campbell et al., 2003; Fox, Dodd, & Howard, 2002; Harrison & McLeod, 2010):

• Male
• Pre- and perinatal problems
• Oral sucking habits (e.g. excessive sucking of pacifiers or thumb)
• Ear, nose, and throat problems
• A more reactive temperament
• Family history of speech and language problems
• Lack of support for learning in the home

The American Speech Language Hearing Association (ASHA) lists some indicators that a child may need intervention including:

• By 3 years cannot:
  • Be understood by family and/or caregivers
  • Correctly produce vowels and such sounds as p, b, m, w in words
  • Repeat when not understood without becoming frustrated
• By 4 years cannot:
  • Be understood by individuals with whom they do not associate regularly
  • Be understood by family and/or caregivers
  • Correctly produce t, d, k, g, f
  • Be asked to repeat without becoming sensitive
• By 5 years cannot:
  • Be understood in all situations by most listeners
  • Correctly produce most speech sounds
  • Be asked to repeat without exhibiting frustration