Acquisition of Speech Sounds

Acquisition of speech sounds occurs from age 2 all the way to age 6. If your child is between 2-3 years of age, we would expect him or her to use the following sounds appropriately: p, b, m, d, n, h, t, k, g, w, ng, f, y. By the time a child reaches 6 years of age, we would generally expect him or her to use all sounds appropriately. The chart below shows the average age children produce each sound appropriately. It’s important to remember that each child’s speech develops differently; however, if your child is demonstrating errors past the expected age of acquisition, it might be beneficial to consider a speech evaluation.


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.


Phonological Disorder

A phonological disorder occurs when a child’s speech is highly unintelligible (difficult to understand), and there are patterns of errors present in their speech. This is different from an articulation disorder where there are errors on individual sounds, such as a child who has difficulty with production of later developing sounds such as /r/, /th/, or /l/. Many children use phonological processes that would be considered typical development; however, it becomes more of a concern if they persist past when we would expect them to disappear. For example, a child may drop the final consonants from many words, which we refer to as “final consonant deletion”. This typically disappears around age 3 so if your 2-year-old does this, we are not as concerned as if a 4-year-old does. There are quite a few phonological processes including cluster reduction (i.e. when a child says “nake” for “snake”), gliding (“wed” for “red” or “wike” for “like), and many others. If your child’s speech is highly unintelligible or you feel they might be using phonological processes, it would be beneficial to consider a speech evaluation to speak with a qualified SLP who can help determine if your child has a phonological disorder. We love using the cycles approach for phonological disorders at our clinic which is a research-based treatment approach that’s been used for a very long time.