Phonological Disorder: Patterns of sound errors, known as Phonological Processes (see chart below for a list of common Phonological Processes).
Processes are deviations from the rules governing how sounds fit together to make words.
(click image for link to chart)
Articulation Disorder: Difficulty producing select sounds due to manner or placement of production. In general, articulation errors consist of: omissions
(ex: "-ug" for "bug"), substitutions (ex: "thee" for "see"), or
distortions (ex: when the sound is distorted, it sounds somewhat similar but is not completely accurate).
Apraxia and Other Motor Speech Disorders: Difficulty with the motor planning necessary for speech production. It is considered an oral
motor planning disorder, and is
not related to oral motor weakness. In contrast, oral motor weakness is characterized by weak articulatory muscles (lips, tongue, cheeks).
Apraxia vs. Speech Delay
Additional Differential Diagnosis for Apraxia
For additional information, refer to: Phonological? Apraxia? Articulation? A great resource comparing Speech Disorders, by Apraxia-Kids.org.
