Breaking Down the Difference: Speech Impediment vs Impairment

Approximately 17.9 million (7.6%) U.S. adults have reported to have a problem with their voice. Speech is made up of the various sounds within language which we use voice to express. Not only is speech the original and most fundamental mode of human communication, but is also one of the foundations of human languages itself. It lets us convey messages, tell stories, answer questions, and express our wants and needs. But what happens when this ability is disturbed?

Having a speech disorder and losing the ability to speak without an impairment of language can be torturous. These disorders are split into two groups: speech impediments and speech impairments. While they are often used interchangeably, there are however some very subtle differences between the two.

Unless you are studying the Ithaca College online SLP program, you might find that distinguishing them is rather difficult. So, let's delve in to understand and learn their differences, as this knowledge may prove to be potentially useful if you or a loved one has a speech disorder. 

What are Speech Impediments?

An impediment generally refers to a specific physical problem or obstacle. Therefore, a speech impediment describes a type of speech problem that is characterized by an obstacle causing difficulties in producing clear speech and sounds. These precise difficulties are directly rooted in the bones and muscles that are used to coordinate speaking.

When we communicate orally, we are not just uttering sounds but also moving our mouths, jaws, tongues, and vocal cords simultaneously to convey intelligible sounds to others. When this coordination is disrupted, it will lead to a speech impediment. 

Types of Speech Impediments 

There is a wide range of speech impediments and there are different categories for them too. Some of these include;

• Apraxia of speech – Approximately 1 to 2 children per 1000 have this neurological disorder. It is characterized by a range of difficulties someone experiences when they want to say a desire to say correctly – but cannot. This is primarily due to the brain struggling to coordinate the movements needed to speak. 
• Lisping – In a survey done on 750 students, around a quarter (23.3%) had a lisp. It is when the ‘s’ or ‘z’ sounds are not pronounced correctly, and it usually happens when the person pronounces them between the teeth rather than behind. 
• Dysarthia – There is an estimated 25-30% prevalence of dysarthria amongst individuals with a motor neurone disorder (MNE). Slurred, choppy, or just unclear speech due to weak or disturbed muscle coordination for speech are the general characteristics of this impediment. 
• Articulation errors – These can be difficulties in pronouncing ‘r’ and ‘l’. The person with the impediment will replace it with other sounds, leading to incorrect pronunciation of the word. For example, they might not be able to say ‘red’ and say ‘wed’ instead. 

Occasionally, speech impediments are a sign of another underlying condition, though they can still occur independently. 

Causes

Different types of speech impairment can have different causes, and these are also dependent on each different individual. Some causes may be;

• Brain damage (e.g. a traumatic brain injury).
• Nervous system damage.
• Respiratory system damage. 
• Hearing difficulties.
• Cancerous or non-cancerous growths.
• Muscle and bone problems particularly in the dental or cleft palate regions. 
• Injury or illness on the vocal cords. 
• Autism spectrum disorder.
• Dementia. 
• Down syndrome or other syndromes.
• Cerebral palsy or other neurological disorders.
• Multiple sclerosis. 

Some speech impediments are also hereditary, so family history may be a cause as well. More benign causes can include mere voice overuse or chronic coughs, both of which can entail speech impediments. 

Treatment

Speech therapy is a recognized method for treating speech impediments. For example, articulation therapy, which focuses on improving the ability to pronounce sounds in speech correctly, can be used for articulation errors. Other therapy methods also include cognitive behavioral therapy (CBT) (e.g. to address stuttering which is commonly associated with anxiety), assistive devices (e.g. digital devices or technology to assist with speech production), and parent and caregiver training (e.g. engaging with parents or caregivers to support speech development at home). 

What are Speech Impairments? 

An impairment generally refers to a non-physical problem or obstacle. As such a speech impairment encompasses a much broader variety of obstacles causing difficulties to communicate effectively. Speech impairments can include speech impediments, but impairments also cover problems in processing or producing language, also known as language disorders.

Types of Speech Impairments 

As it covers a wide range of communication disorders, the following are some examples of the most common speech impairment disorders;

• Aphasia – More than 2 million people in the U.S. are estimated to have a form of aphasia. It is a language disorder caused by damage to a specific part of the brain that is responsible for processing and expressing language. Aphasia does not impact intelligence, but it can nevertheless exert a significant impact on how an individual communicates in speech. 
• Cognitive-communication disorders (CCD) – Approximately 1.4 million individuals have stroke-related CCDs each year. It refers to problems in communication that arise from any cognitive impairment or damage to the brain. This can manifest in difficulties organizing thoughts and expressing them in speech or following conversations. 
• Selective mutism – This most commonly occurs amongst children as it is an anxiety disorder where a child consistently fails to speak in certain social situations, despite speaking in others. 
• Voice issues – From things such as hypernasality (excessive nasal resonance) and hyponasality (insufficient nasal resonance), also known as resonance disorders, to problems in pitch and volume when speaking, speech clarity can be significantly affected by either. They can also change the way one’s voice sounds. 

Causes

Like speech impediments, there are also a variety of causes of speech impairments. These can be;

• Neurodevelopmental conditions.
• Traumatic brain injuries. 
• Structural abnormalities. 
• Medical conditions. 
• Mental health disorders. 

Moreover, speech impairments can either be hereditary or non-hereditary. Environmental influences such as stress or a lack of exposure to language are important non-hereditary factors for the development of speech impairments. In contrast, syndromes such as Fragile X can be a hereditary factor for delayed speech and language development, leading to potential future impairments in speech. 

Treatment

Besides speech and language therapy, methods such as augmentative and alternative communication (AAC), which is the use of communication devices or technologies for individuals with severe communication challenges; or neurorehabilitation that aims to restore speech or language abilities for individuals who have lost them (which can be particularly useful for those who have impaired speech due to a medical conditions like stroke), are some other recognized ways to help with speech impairments. Ultimately, however, personalized treatment plans are still the key to effectively addressing the unique circumstances of each individual’s speech impairment difficulties. 

For more information about speech, communication, and language disorders, you can always visit the American Speech-Language-Hearing Association (ASHA) for more specified information about certain speech disorders.