Articulation disorders are speech errors characterized by distortions or substitutions of specific speech sounds. For example, a common articulation disorder is a interdental lisp, which can be most noticeable during production of sounds such as /s, z, sh, ch, j/.
When talking, children with articulation disorders may drop, replace, or incorrectly produce sounds or syllables. Risk factors associated with development speech sound errors include differences in muscle tone, presence of developmental disorders, persistent thumb-sucking, family history of speech difficulties, ear infections and/or hearing loss.
Speech sounds tend to develop along the timeline depicted in the chart below. If your child is within the range for development for a certain speech sound, but is unable to produce the sound at all or consistently produces the sound incorrectly (ie. production of the speech sound does not seem to be progressing over an extended period of time), it may be time to consult a speech-language therapist.
Evaluation often involves standardized testing to determine presence and severity of the disorder. During evaluation, the child is prompted to say words and/or sentences. Responses are transcribed in order to identify specific sounds that are produced incorrectly. Evaluation may also assess intelligibility (how often familiar and unfamiliar listeners understand the child) and stimulability (child’s ability to produce specific speech sounds given explicit teaching and models).
Treatment for articulation disorders varies depending on type and severity. In most cases, speech sounds which are anticipated to be produced the earliest are targeted first. Once specific target sounds are identified, treatment for articulation disorders often involves explicit teaching about place (where our articulators are positioned), manner (how the sound is produced) and voicing (voiced or voiceless sounds). In early stages, children generally learn to produce the sound on its own. During this stage, children may need physical supports (e.g. using a popsicle stick to hold down the tip of the tongue in order to produce /k/). With consistent practice, children can become more independent in production. Throughout treatment, children progress from producing sounds in words, to phrases, to sentences and then to natural speech. Treatment of articulation disorders can sometimes be a lengthy process. However, home practice can help to support the development of articulation.
Speech Sound Disorders: Articulation and Phonology (asha.org)