(Dyspraxia, Dysarthria, SSD – Speech Sound Disorder – including articulatory or phonological disorders)

Speech articulation is a complex and rapidly coordinated cognitive and sensori-motor act.

Let’s consider that:
Each speech sound has 3 defining features: place, manner and voiced or unvoiced.
For example, /p/ is the same as /b/, but b is voiced, /t/ is articulated in the same place in the mouth as /s/, but /t/ is a stop consonant and /s/ is a continuant, /f/ involves the lips and teeth, /th/ the tongue and teeth and so on.
Vowels are determined by mouth shaping (lips and tongue).
Intelligibility can be determined by the articulatory complexity of the word and the cognitive complexity of the spoken intent.

Now, imagine I want to say the “dog” but it comes out wrong.
Assessment will tell us the source of the problem:
Semantics? (not sure of the word, saying the wrong word), (It came out as “cat”)
Motor programming – sure of the word but the brain got the programming signals to the muscles mixed (affecting accuracy and timing of articulation) It came out as “gock”.
Sensori-motor weakness and/or incoordination – at the muscular level. It was unintelligible. Something with “o”???
For children, the issue may be the above and/or neurological readiness (developmental).

Assessment behaviours and outcomes guide the appropriate interventions.