Speech refers the clarity of our speech: How we pronounce our words, and how well we are understood when we speak, rather than the words we are saying, or our ideas we are communicating. Speech disorders are sometimes due to delays in normal speech acquisition patterns, other times they are due to motor weakness, coordination or both. Speech disorders can occur for no known reason, physical disability or neurological disability; a result of development — or acquired due to brain injury. Still others speech difficulties are due to craniofacial disorders such as cleft-palate, and structural/ functional disorders such as the complexity of issues related to the function of the tongue in relation to the oral cavity structure.
In all cases, therapy begins with an evaluation, to determine the particular factors involved, and re-training the incorrect placement and movements of the “articulators” (tongue, lips, and jaw) within the oral cavity, in a systematic simpler-to-harder hierarchy of steps that are tailored to each individual.
When typical speech sound-pattern pattern development gets “stuck.” The more sound patterns are affected, the more difficult the child is to understand.
Specific speech sound errors (e.g. Lisps and R problems)
When overall speech is clear, but one or two sounds, are “off.” Typically this is associated with distortions of the “s” and/or “r” sounds.
Motor Speech Disorders (muscle movement disorders)
Muscle weakness that causes a slurred, imprecise speech quality. This might be the result of a stroke or neurological condition, or it could be developmental in nature without a clear reason.
Apraxia of Speech/Childhood Apraxia of Speech
The muscles have adequate strength for precision but there is poor coordination of movement of the tongue, lip and jaw muscles, and possibly with breathing as well. People with this difficulty may say words differently from one time to the next, and have greater difficulty with multisyllabic words and longer sentences. This disorder can be acquired due to brain trauma such as a CVA or developmental in nature.
Structural / Functional Disorders
When the soft palate cannot make a seal, or if there are spaces in the hard palate, the voice/resonance quality becomes hypernasal. This creates distortions of the sounds of speech, due to the hypernasality itself as well as the compensations for this condition with an atypical production of speech sounds. The job here is to promote as much oral production as the structure allows and to re-train the incorrect speech sound productions.
Oro-Myofunctional-based Speech Disorders (see Orofacial Myology Disorders)
Although there is a great deal more involved with oro-myofunctional disorders, in terms of speech production, OMD affects speech mostly due to low tongue posture or an actual “tongue thrust” against or through the teeth typically affecting the production of sounds involving tongue tip to the palate right behind the upper teeth. These include lisps on, s, z, sh, and j sounds and distorted productions of d, t, n, l, and r. However, other sounds can also be affected as well as oral structures in general. (see orofacial myology for a greater perspective..)
Tongue Ties/ Lip Ties
Tongue and lip (and even cheek) ties, also known as tethered oral tissue, restrict the movements of the tongue and lips–creating the tongue tip speech difficulties listed above and lip sounds such as p,b,and m– but may also contribute to overall difficulties in speech clarity. (Tethered tissue contribute to myofunctional/orofacial myology disorders.)