Question

What areas/mechanisms are involved in speech production and comprehension? Discuss the major speech problems, their signs and symptoms, and possible causes/mechanisms.

Answer 1

TSpeech organs, or articulators,produce the sounds of language.There are several areas of the brain involved in speech production and comprehension.Both left and right hemispheres of the brain are instrumental in this effort.The left hemisphere deals with the production and comprehension of speech whereas right hemishphere is necessary for communication as this area deals in figurative components of speech such as understanding metaphors.An area in the left hemisphere of the brain callde Broca's area plays an important role in speech production. This area contains neurons that deals with the function of speech creation and understanding language.It is located in the frontal left hemisphere rostral to the primary motor cortex and is necessary for fluent and effective speech.

Speech disorders affect a person's ability to form the sounds that allow them to communicate with other people.Some types of speech disorder include stuttering,apraxia and dysarthria.

1) STUTTERING

It refers to a speech disorder that interrupts the flow of speech that causes repetitions,blocks and prolongation of particular sounds or words,which is caused by a stroke,traumatic brain injury,or other brain disorder.Further it is of two types -

a) Developmental stuttering :-It affects young children who are still learning speech and language skills through genetic factors.

b) Neurogenic stuttering :- It occurs when damage to the brain prevents proper coordination between the different regions of the brain that play important role in speech

2) APRAXIA

It refers when brain damage that impairs a person's motor skills,that affect an individual's ability to form the sounds of speech correctly,even when they know which words they want to say.There is difficulty striging syllables together in the appropriate order to make words,difficulty saying long or complex words,excessive use of nonverbal forms of communication,grammatical problems,clumsiness etc.There are two forms of apraxia-

a) Acquired apraxia:- which can occur in people of all ages,which causes people to lose the speech-making abilities they once possessed due to any kind of brain damage

b) Childhood apraxia:-It is present from birth and it affects a child's ability to form sounds and words,which may be caused from signaling problems between the brain and the muscles used for speaking.

3) DYSARTHRIA

Also called slurred speech,occurs when damage to the brain causes muscle weakness in a person's face that is lips,tongue or chest.Muscle weakness in these parts of the body can make speaking very difficult.Its symptoms may include slurred speech,mumbling,speaking too slowly,difficulty in moving the mouth or tongue etc.It can be due to nervous system disorder,head injury,stroke,wilson's disease,extreme fatigue,intoxication,recent oral anaesthesia etc.It can be of many types :-

a) Flaccid dysarthria

b) Spastic dysarthria

c) Ataxic dysarthria

d) Hypokinetic dysarthria

e) Hyperkinetic dysarthria

4) OROFACIAL MYOFUNCTIONAL DISORDER

It refers to problem encountered when the tongue thrusts forward inappropriately during speech.It symptoms include limited tongue movement,someone who always breathes through the mouth,drooling,difficulty closing the lips to swallow.It is caused by blocked nasal passages,anything that causes the tongue to be misplaced at rest or sucking and chewing habits.

5) SPEECH SOUND DISORDER

It is a communication disorder in which children or adults have persistent difficulty saying words or sounds correctly.The person may subsitute one sound for another,leave sounds out,add sounds,or change a sound.It may be caused due to developmental disorder like autism,genetic syndrome,hearing loss or brain damage like cerebal palsy or a head injury .