What is a speech disorder?

Articulation is the oral motor movements during the production of speech sounds. Correct production of speech requires: 1) neurological ability, 2) respiration, 3) larynx activity (voice box), 4) movement of the articulators: tongue, lips, teeth, hard palate, soft palate and jaw, and 5) adequate hearing.

 Articulation skills typically follow a developmental sequence.  The research indicates that 90% of children acquire the following consonants by the age given below (Sanders, 1972).

 Age 3:  p, m, h, n, w

Age 4:  b, k, g, d, f, y

Age 6:  t, ng, r, l

Age 7: ch, sh, j, th

Age 8:  s, z, v, th, zh

What are some common articulation errors for children?

The most frequently misarticulated sounds are “r” and “s”. 

     Typical errors of the “r” include distorting the “r” or substituting “w” or the vowel in “would” for “r”.   Some examples are “wabbit” for “rabbit” and “boud” for “bird”.

      Typical errors of the “s” are distortions and substitutions.  Common substitutions are “t” and “th” for “s”.  Some example are “ting” or “thing” for “sing”.  Sometimes the term “frontal lisp” is used to refer to the “th” for “s” substitution.  This descriptor is used to indicate the tongue is sticking out between the front teeth during an attempted /s/ sound.   Additionally, the term “lateral lisp” is sometimes used to describe the slushy sounding production of /s/ when the tongue is in the position for the /l/ sound. 

Other common errors in school aged children are “l”, “ch”, “j” and “th”.

Phonology is the study of speech sound and the rule system for combining sounds into words.  This includes the ability to hear differences in sounds, identify where a sound is in a word (/t/ in cat is the ending sound), and produce speech sounds with correct articulation.

As children develop language and speech patterns, they naturally simplify adult forms that are difficult for them to produce. These new patterns are termed phonological processes.  Examples of common phonological processes are: 

1. Deletion of final consonants (“top” is “to__”
2. Deletion of unstressed syllable (“about” is “bout”)
3. Cluster or blend reduction (“star” is “tar”)
4. Assimilation, one sound in a word affects another sound (“dog” is “gog”)
5. Fronting, sounds made in the back of the mouth now made in the front (“back” is “bat”)  (McReynolds, 1986). 

As a child matures, these processes should disappear and be replaced by the adult form.  If they do not disappear, the child may have a phonological disorder.

Stuttering is speech that has irregularities that include repetitions of sounds, syllables, or words; or prolongation of sounds or syllables.  All speech is characterized by pauses and some repetitions, especially in young children.  Stuttering interferes with the forward flow of speech.

            Stuttering may be mild or severe.  Most stuttering begins by easy syllable repetitions or prolongations of sounds.  Facial grimaces and struggle behavior may accompany these repetitions.  Some children experience anxiety, fear, frustration, and/or hostility. However, not al children who stutter respond alike to the stress connected with it. Stuttering may be mild or severe. 

Voice disorders is when a speaker’s voice is significantly different from the norm in one or more dimension:  pitch, loudness, or quality.

            Pitch:  A speaker’s pitch may be too high or too low for that particular person. 

            Loudness:  A speaker’s loudness level may be too high or too low.

Quality:  A speaker’s vocal quality is described as hoarse, harsh, breathy, grating, monotone, hypernasal (too much), or hyponasal (not enough).

 Most voice disorders appear to be a result of the following causes.

1. Vocal abuse or vocal misuse. Examples are screaming, yelling, shrieking, excessive use, loud laughter, throat clearing, and smoking.
2. Vocal nodules.  Due to abuse, swelling and eventual protrusions develop on the vocal folds.
3. Papillomata.  These are the most common laryngeal tumors found in children.
4. Polyps.  These may be present due to single instance of abuse.
5. Hyponasality.  Often due to colds, allergies, respiratory infections, or enlarged adenoids; the space between the soft palate and wall of the throat are filled up and do not allow air to reach the nasal cavity.
6. Hypernasality.  This occurs when the nasal cavity cannot be sufficiently shut off from the oral cavity and all sounds have a nasal quality.  This may result from a cleft palate, short velum, neurological problems, or hearing impairment.

References:

McReynolds, L.V. (1986). Functional articulation disorders. In G.H. Shames and E.H. Wiig (Eds.) (2^nd ed.)  Human         communication disorders  pp. 139-182).  Columbus,          OH:  Charles E. Merrill.

 Owens, R.E., Jr. (1984).  Language development. An             introduction  Columbus, OH:  Charles E. Merrill.

 Oyer, H. J. (1987).   Speech, language, and hearing disorders:  A guide for teachers.  Boston, MA:  Little, Brown and Company. 

Sander, E. (1972).  When are speech sounds learned?  Journal of Speech and Hearing Research, 37, 55-63.