Articulation and Phonological Disorders
Most children make some mistakes as they learn to say new words. A speech sound disorder occurs when mistakes continue past a certain age. Every sound has a different range of ages when the child should make the sound correctly. Speech sound disorders include problems with articulation (making sounds) and phonological processes (sound patterns).
An articulation disorder involves problems making sounds. Sounds can be substituted, left off, added or changed. Young children often make speech errors. For instance, many children sound like they are making a “w” sound for an “r” or an “l” sound (e.g., “wabbit” for “rabbit” or “weaf” for “leaf”). ‘The child may have an articulation disorder if these errors continue past the expected age.
Articulation development follows an orderly sequence and developmental error patterns are to be expected at each stage in development. Increased coordination of the muscles in the lips, tongue, jaw and soft palate are required for later developing sounds such as r, th and l.
The following demonstrates the general age ranges in which the correct production of these sounds should appear:
- By two years: p,b,d,t,m,n,w,h
- By four years: k,g,f,v,ing,
- By five years: s,z,ch,sh,j, l
- By six to seven years: r,th
While some children may have difficulty with one or two sounds, other children have difficulty with a whole group of sounds that share similar characteristics. These are known as phonological processes. Phonological processes are a normal part of speech development however when these error patterns persist beyond developmental norms, a child is described as having a phonological process disorder.
Examples of phonological processes seen in very young children include:
1. Syllable deletion: the child leaves out the unstressed syllables in words e.g. says “nana” for banana
2. Final consonant deletion: the child leaves off the ending consonant in words e.g. says “da” for dog.
3. Reduplication of sounds or syllables: the child may say “baba” for bottle or “gog” for dog.
4. Velar fronting: the child substitutes all sounds made in the back of the mouth like “k” and “g” for those in the front of the mouth like “t” and “d” e.g. saying “tup” for cup or “do” for “go”.
Children with a history of a phonological process disorder are at higher risk for experiencing difficulty in literacy development because they demonstrate struggle with the phonological component of language which is the underlying cause of reading disabilities such as dyslexia.
What causes speech sound disorders?
Many speech sound disorders occur without a known cause. A child may not learn how to produce sounds correctly or may not learn the rules of speech sounds on his or her own. These children may have a problem with speech development, which does not always mean that they will simply outgrow it by themselves. Many children do develop speech sounds over time but those who do not often need the services of a speech language pathologist to learn correct speech sounds.
Some speech sound errors can result from physical problems, such as:
- developmental disorders (e.g. Autism)
- genetic syndromes (e.g., Down syndrome)
- hearing loss
- neurological disorders (e.g., cerebral palsy)
Children who experience frequent ear infections when they were young are at risk for speech sound disorders if the ear infections were accompanied by hearing loss.
Speaking with an accent and/or dialect is not a speech sound disorder.