Acquisition of Speech Sounds
Intelligibility refers to the ability to understand a speaker’s message. As SLPs, we always report on intelligibility of speech as decreased intelligibility significantly impacts a child’s ability to be a functional communicator. When intelligibility is decreased, children may have difficulty expressing his/her wants and needs, and may get frustrated when he/she is unable to get his/her message across. The old standard for intelligible speech has always been 50% intelligible by age 2; 75% intelligible by age 3; and 100% intelligible by age 4; however, a recent study was published indicating that intelligibility is much more complicated and progresses much more slowly than this. Intelligibility grows the most from 30-41 months of age. Below is a chart that shows the median, and milestone averages in intelligibility from age 3-7. As you can see from the chart, there is much more variability with intelligibility up to age 7. These authors indicate based on this new study that children should be 50% intelligible by age 4, 75% intelligible by age 5, and 90% intelligible by age 7.