Speech is a complex process requiring precise breath timing, clear brain signals and coordination of muscles in the larynx, lips, tongue and mouth. Voice fluency is the unrestricted flow of a person's spoken words. Natural unrehearsed speech has a normal degree of disfluency. In her 2001 article "To 'errrr' is human: ecology and acoustics of speech disfluencies," Elizabeth Shriberg notes that 10 percent of words and one-third of utterances have filled pauses ("um," "uh," "ah") repetitions of words ("the, the family") or repairs ("his, I mean her"). When fluency errors regularly go above this amount, medical professionals will suspect a language or voice disorder.
Stuttering and Cluttering
Stuttering is probably the most recognized voice fluency disorder. A person who stutters may repeat the first part of a word (c-c-c-car) or hold a single sound within a word (haaaaave). In "Neurology in Clinical Practice," Walter Bradley notes that stuttering is often inherited, possibly as an abnormal connection between the two halves of the brain.
In cluttering, the person will have incomplete sentences, speak short two or three word phrases or repeat the last words he has heard (echolalia). The unexpected pauses and bursts of speech result in awkward conversation. Stuttering often accompanies cluttering. Bradley states that cluttering happens in fragile X syndrome, a genetically inherited condition.
Spasmodic Dysphonia
SD is a disorder of the central nervous system caused by spasms of the muscles in the larynx. The larynx contains the voice box, or vocal cords. Spurts of a strangled-sounding voice or a breathy soundless voice interrupt the person's normal speaking. Swallowing and breathing itself are not affected. The cause is unknown, but the Voice Problem website notes that injections of botulism toxin repeated every three months can help relieve symptoms.
Verbal Apraxia
Verbal apraxia, or dyspraxia, is a motor speech disorder caused by damage to the areas of the brain that control the voice. Causes range from accidents to stroke, birth injury or a genetic disorder. The severity of the voice fluency problem varies with the type of brain damage. Patients suffer with trouble sequencing sounds and words. It is frustrating, as the patient knows what he wants to say, but is unable to coordinate his muscles to say the correct words. Replacement (house instead of hair) or nonsense words (hercan) may come out instead. According to the American Speech-Language-Hearing Association, in some cases the patient is taught sign language as an alternate form of communication.
Articulation Disorders
Patients with articulation disorders make errors when speaking. The Teens Health website notes that a person may replace "w" with "r" ("wascal" instead of "rascal") or lisp, which is specifically substituting the letters "s" and "z" with "th." Some patients omit word sounds, saying "hicle" for "vehicle" or adding sounds to words, saying "remotcol control" for "remote control." Patients with this type of voice fluency disorder should be screened for hearing loss.
Therapy
Speech and language therapy is a group of treatments for communication disorders. Speech-language pathologists, also known as speech therapists, provide this therapy. Treatment includes exercises to create speech sounds, as well as breathing control and muscle relaxation exercises. Therapy may initially be as often as three to five days a week, declining in regularity as the voice fluency problem improves. The American Speech-Language-Hearing Association notes that practicing the exercises at home is important to successful treatment.
References
- "Journal of the International Phonetic Association"; To 'errrr' is human: ecology and acoustics of speech disfluencies; Elizabeth Shriberg; 2001
- TeensHealth: Speech Problems
- "Neurology in Clinical Practice: The neurological disorders"; Walter George Bradley; 2004
- Voice Problem: Spasmodic Dysphonia
- American Speech-Language-Hearing Association: Apraxia of Speech in Adults
