Speech Development: Phonological Processes and Phonological Delay

A child’s speech development is not just about his/her articulation skills (as I discussed in my last post). When SLPs are assessing a child’s speech we are also looking at the sound patterns that the child is (or is not) producing correctly. These patterns are called phonological processes and today I am going to tell you all about them!

What is phonology?

Phonology is the study of how speech sounds (i.e. phonemes) are organized and used in a language. This includes the study of the individual sounds of a language (phonemes), their patterns, how they are learned (phonological development) and how they work and go together.

You see, all the sounds in English are organized and classified into different classes based on the sound’s place (where in the oral cavity they are produced), voice (if the sound requires voice, like b,d,g vs an unvoiced sound as in p,t,k) and manner (the “manner”  in which the articulators alter the vocal tract and the degree or type of closure of the vocal tract when producing a sound). Though these classes of sounds may not seem very interesting to the average person, this information can become very important when trying to assess and treat a child with very unintelligible speech.

What are phonological processes?

Simple answer: They are the typical patterns of how a child simplifies his speech (so “normal” speech sound errors) as they learn to speak. A child is not born being able to produce all the sounds and sound patterns of his/her language. As a child is learning how to speak English, he will simplify sounds and sound patterns. For example, a young child will simplify the word “bottle” to something like “baba.” A young child may also say “goggie” for “doggie,” “sue” for “shoe,” or “nail” for “snail.” Phonological processes, then, are the normal patterns of simplification all children use as they are learning to speak. Just like articulation skills, every child will develop their phonology skills differently, but there are ages when a child should stop using different phonological processes.

Here is a chart defining the different phonological processes and the age in which they should no longer be used.

What is a Phonological Delay?

A phonological delay refers to when a child is continuing to simplify his speech (using these phonological processes) beyond the typical ages of use (see my Common Phonological Processes Chart). A child with a severe phonological delay may even be simplifying his speech so much that he is only producing a few different sounds when he should be able to produce many sounds (this is when those “classes” of sounds can come in handy). Children with phonological delays tend to be quite hard to understand, especially to strangers (parents often learn their child’s patterns and therefore can understand them better).

What is the cause of a Phonological Delay?

Well, we don’t actually know for sure what causes a phonological delay. It does NOT, however, appear that it is a result of anything a parent is doing -or not doing- at home. According to Speech-Language Pathologist Caroline Bowen, PhD,who has done research and written books on the subject, there are five possible causes based on the research to date. She listed them on her website, www.speech-language-therapy.com  in an answer to a parent:

1. The child finds the sound patterns of language totally confusing and cannot make out sound details form the overall pattern of sounds in language.
2. The child’s speech maturation (readiness) may be severely delayed;
3. The restricted speech system becomes “habit”, suppressing further speech maturation;
4. The child has poor perception and awareness of how their speech sounds, and the difficulty other people have understanding them when they talk;
5. The child has a specific difficulty initiating changes in their sound
system, and knowing how to organize their sound system in a consistent way.

How can I tell if my child has a phonological delay?

The only way to know for sure, is to have your child assessed by a speech-language pathologist (Click here to find out how to find an SLP in your area  ). However, here are some red flags to look out for:

1. Your child deleting the initial sounds in many of his words (called Initial Consonant Deletion). For example, “ig” for pig or “ed” for Bed.
2. Your child is deleting the ends of most of his words (called Final Consonant Deletion). For example, “beh” for bed or “pih” for pig
3. Your child is substituting “back sounds” (like k, g, h, ng) for sounds that are produced at the front of the mouth (like t, d, p, b, m, etc). For example, “kop” for top.
4. Your child is having difficulty producing numerous vowel sounds
5. Your child’s speech is very hard for others to understand at the third birthday (A good general rule of thumb for how intelligible, or how much of your child’s speech you should be able to understand, is the child’s age in years divided by 4 (Reference:  Coplan, J., & Gleason, J. R. (1988). So 2 years old = 2/4 or 50%, 3 years old = 3/4 or 75%, 4 years old = 4/4 or 100%.)

If you haven’t already, make sure to read my post all about articulation development to get the “whole” picture of your child’s speech development.

**************************************************************************************************

References:
Bowen, Caroline, (1998). Typical speech development: A gradual acquisition of the speech sound system.  Retrieved from http://speech-language-therapy.com/acquisition.html.

Shipley, K.G. & McAfee, J.G.,(1998). Assessment in speech-language pathology: A resource manual (2nd edition). San Diego, CA: Singular Publishing Group.

Williams, A. Lynn, (2003). Speech disorders resource guide for preschool children. Clifton Park, NY: Singular Publishing Group.