What is the Critical Age Hypothesis?

And how does it apply to your child?

The Critical Age Hypothesis is the idea that a child needs to be intelligible by the age of 5 years, 6 months (5 1/2 years old) in order to be able to produce sounds accurately and comparably to others their age, and to succeed academically. A child is considered "intelligible" when (s)he is almost always able to be understood by others and produces minimal errors when speaking. Overall, it is generally believed that children need to acquire and accurately use all sounds by the age of 6 years.

Prior to the age of 6, intelligibility is expected to be at the following rates:

(please note that these numbers relate to intelligibility by parents)

By 18 months: approximately 25% intelligible

By 24 months (2 years): approximately 50%-75% intelligible

By 36 months (3 years): approximately 75%-100% intelligible

It's very important to target sound production by preschool in order to give speech delayed kiddos a better chance at success academically as well as personally in their relationships with others.

If you suspect that your child is delayed or that speech intelligibility is lower than the estimates above, contact us for a consultation or to ask questions!

SOURCES:

Critical Age Hypothesis: (Bishop & Adams)

Sound Acquisition: ASHA

Intelligibility: Bowen, C. (2011). Table1: Intelligibility. Retrieved from http://www.speech-language-therapy.com/ on 2020/09/11.