An articulation disorder involves problems making sounds. Sounds can be substituted, left off, added or changed making it hard for people to understand the speaker. Your child may have an articulation disorder if the sound errors continue past the expected age of development.
How intelligible should your child be?
AGE INTELLIGIBILITY TO AN UNKNOWN LISTENER
18 months 25%
2 years 50-70%
3 years 80%
4 years 90-100%