Single-word intelligibility
“ball”
The listener hears one word at a time, with nothing around it to help them guess. It shows how clearly your child makes the sounds in each word. It's often measured by having a child name pictures.
Intelligibility is how much of what your child says a listener can understand. Parents and siblings usually understand far more than anyone else, because they know the child's words, routines, and favorite topics.
That's why intelligibility is measured with unfamiliar listeners: adults who have never heard the child before. All the numbers on this page are about how well strangers understand a child.
Single words and connected speech
Intelligibility is measured two ways, and a child can be easier to understand in one than the other.
Connected speech intelligibility
“I want the red ball”
The listener hears sentences or conversation, the way your child talks every day. The other words help listeners fill in gaps, so from about age 3½, typical children are understood a little better in sentences than in single words. But some children, especially those with speech sound disorders, are clear one word at a time and much harder to follow once they string words together.
How much strangers understand, by age
Pick your child's age to see how much of a typical child's speech strangers understand, in single words and in sentences.
How old is your child?
At 4 years, strangers typically understand 74% of a child’s single words and 79% of their sentences.
See all ages as a table
| Age | Single words, typical | Sentences, typical | Single words, low end | Sentences, low end |
|---|---|---|---|---|
| 2½ years | 48% | 41% | 24% | 12% |
| 3 years | 58% | 56% | 34% | 26% |
| 3½ years | 67% | 69% | 44% | 41% |
| 4 years | 74% | 79% | 52% | 55% |
| 5 years | 83% | 89% | 64% | 74% |
| 6 years | 88% | 94% | 71% | 84% |
| 7 years | 90% | 96% | 75% | 89% |
| 8 years | 92% | 97% | 77% | 93% |
| 9 years | 93% | 98% | 78% | 95% |
Good to know
- By age 4, even children at the low end of typical are understood more than 50% of the time.
- Around age 3½, typical children start being understood better in sentences than in single words.
- Growth is fastest around age 2½, then keeps going steadily well into the school years.
- Hard-to-understand speech often comes from sound patterns children haven't outgrown yet. See speech sounds by age and our guide to phonological processes.
When to talk to a speech-language pathologist
- By age 4, people outside your family understand less than 50% of what your child says.
- Your child is understood less than the low end of typical for their age on the chart above.
- Your child is clear in single words but hard to follow in sentences.
- Your child gets frustrated, or avoids talking, because they aren’t understood.
You don't need to wait and see. We offer free phone consultations: talk with one of our speech-language pathologists about what you're hearing and whether an assessment makes sense.
Call 617-419-0424 or email hello@tlcspeechtherapy.com.
Source
Hustad, K. C., Mahr, T. J., Natzke, P., & Rathouz, P. J. (2021). Speech development between 30 and 119 months in typical children I: Intelligibility growth curves for single-word and multiword productions. Journal of Speech, Language, and Hearing Research, 64(10), 3707–3719.