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The Speech Therapy Blog

What Causes Speech Impediments and Disorders?

Last updated Oct. 9, 2017

Speech impediments are very frustrating. They can be embarrassing for the speaker and draining for their loved ones who want to try to help them.

A speech impediment is defined as having a difficulty with vocal communication.


Some examples of speech impediments include:

  • Slowed, rapid, or slurred speech
  • Hoarseness
  • Stuttering


Patients who experience a speech impediment may also experience:

  • Drooling
  • Trouble remembering words
  • Expressive language reductions
  • Weakened facial muscles
  • Contraction of the vocal muscles


Many people experience speech disorders. Some impediments are common and others rarer. What causes them? How do they develop and how does one rectify them?

We will explore some of those impediments here and their reasons for being:


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Many things can create a speech impediment in a child. A common form of impediment is a developed stutter or stammer.

This occurs when the child’s flow of speech is broken by the child repeating words or phrases. A child who stammers may also extend the length of sounds, syllables or words.

They can also have problems beginning a sentence. In most cases stuttering is not a problem and the child will outgrow it.

If the stuttering persists, the parent may want to have the child checked by their GP or a specialist Speech Pathologist.


Speech Delays:

A delay of speech is another common speech impediment and occurs in 5-10 percent of the preschool population.

There are set levels that a child should achieve in speech formation from birth to between 5 to 6 years of age.

If the parent feels that the child’s speech has been delayed, then they should consult a doctor to have the child’s hearing checked first. Hearing loss is generally common and can mostly be rectified.

Even if the child seems to hear fine at home, their hearing should still be checked as children are experts at picking up non-verbal cues and responding, but not actually hearing their environment.

Some children merely have a system that develops later than normal. These “late bloomers” may have delayed speech or it may be something more serious.

At any suspicion of a language disorder, the parent must get the child medical help. The quicker it is caught; the more successful treatment can be.




So, what causes speech impediments? There are several reasons. Among them are:

  • Apraxia: This disorder occurs when the child has a difficult time sequencing and producing speech movements.
  • Developmental speech and language disorder: This is a common cause for speech problems in children. It is categorized as a learning disability caused by the brain working differently than normal. Often, children diagnosed with this disorder experience problems with using speech to communicate, making sounds of speech, and understanding when others speak.
  • Premature birth: A child that is born premature will commonly experience a language delay as well as other delays in growth and development.
  • Hearing Loss: This cause is common and it is often the most overlooked cause for problems in speech.
  • Auditory Processing Disorder: This disorder creates disturbances when the brain tries to decode sounds in speech.
  • Autism: This disorder also affects speech and communication. Different levels of autism will experience different impediments or none depending on the functioning level of the child.
  • Neurological Problems: Illness such as cerebral palsy, muscular dystrophy, and others can affect the physical muscles needed for making speech and sounds.
  • Traumatic Brain Injury
  • Cleft Palate or lip: A cleft is known as an orofacial defect. This happens in the baby’s development inside the womb. These can cause impediments in children and adults. Most cases can be fixed through surgical procedures.
  • Selective Mutism: This is when the child will simply not speak due to a situation beyond their control.


Adult Speech Impediments:

When adults experience a speech impediment that was not there before, it can be caused by different things.

Impediments can develop quite suddenly or slowly over time. Most can be treated by speech therapists to improve the quality of speech and language ability.

Speech impediments in adults can be caused because of:

  • Medical trauma such as a stroke
  • Brain injury
  • dementia
  • Injury or illness that has damaged the vocal cords
  • Degenerative neurological or motor disorder



Straining the voice or using it incorrectly can cause temporary or permanent damage to the vocal cords.

A long period of time spent yelling, screaming, growling, singing, or making other noises can develop a strain that will result in hoarseness.





Patients suffering from Aphasia usually have this after a traumatic incident to the health such as stroke or brain damage.

Aphasia involves an impairment in the process of thinking of words or pronouncing them correctly and can be caused by:

  • Brain tumor
  • Stroke
  • Head trauma
  • Cognitive degenerative conditions like Alzheimer’s disease



Dysarthria is a physical impairment that involves trouble moving the muscles in the tongue, lips, diaphragm and or vocal cords.

Dysarthria can be caused by many things including:

  • Head trauma
  • Stoke
  • Brain tumor
  • Multiple sclerosis
  • Muscular dystrophy
  • Cerebral palsy
  • Lyme disease
  • Parkinson’s disease
  • Facial paralysis
  • Alcohol
  • Ill-fitting dentures


Vocal Interruptions:

When there is a disturbance in the vocal cords, it can cause a speech impediment.

These disturbances may make it very difficult to speak and damaging to the vocal cords. Vocal interruptions can be caused by many things including:

  • Polyps, nodules, or growths on the vocal cords
  • Caffeine
  • Prescription medications such as antidepressants, and amphetamines
  • Throat cancer


Drug Use:

Taking certain prescription drugs or excessively using illegal drugs can result in a speech impediment.

The speech impediment should leave over time once a certain drug or medication is stopped. Illegal drug use is a serious matter that needs intervention to stop. Talk to your doctor about a safe treatment.


Hearing Loss:

Hearing loss will also cause a speech impediment. This is caused because the speaker cannot hear their voice or their speech.

A partial hearing loss can also affect the clarity of speech. Hearing aids may need to be used to improve hearing.

A speech pathologist will be able to help the patient compensate for the loss of hearing and learn to develop clearer speech patterns.




If you, or your loved one, experience a sudden speech impediment, it is necessary to get medical attention as soon as possible as this may be a sign of more serious medical problems such as a stroke and/or heart attack.

A speech therapist will help to diagnose the problem and then set a plan for treatment to help the speaker overcome their limitations.

Most speech impediments can be rectified through treatment. The soonest a patient seeks treatment, the better their success rate. Communication is a key to life.

Communication is important whether it is performed verbally or non-verbally. A speech therapist is there to help and teach others how to communicate with the world around them.

Contact us if you have any questions.