There are several reasons why children’s speech may be unclear, or why they cannot produce all of the sounds in the English language. It can be cumbersome explaining these reasons to parents, who may look at me blankly when I say that their child has a phonological delay or disorder. Broadly speaking, phonology refers to the study of speech sounds and the rules that govern how sounds are combined in meaningful ways (to create words, sentences, and conversations). When looking at the speech of typically developing children, we see that many speech errors can be grouped or classified in particular ways as they acquire more adult-like speech forms. Here is an example of an error you may see in a 2-3 year old child:
Adult: “Spider!” Child: “Pidew”
The child cannot yet produce the more complex adult form and simplifies it by deleting a consonant at the beginning and changing the ‘r’ at the end to a vowel sound. SLPs use knowledge of common phonological patterns to help determine whether or not a child is following a typical developmental path. There are also some phonological patterns that are not usually seen in children; therefore, when these are observed in a child it can signal atypical speech development.
Articulation errors differ from phonologically based errors because we see that the sound or sounds in question are still within the same phonemic class, but are produced in an atypical way. Children who have a lisp or a persistent ‘r’ distortion are common examples of articulation difficulties.