10 Most Common Speech-Language Disorders & Impediments

As you get to know more about the field of speech-language pathology you’ll increasingly realize why SLPs are required to earn at least a master’s degree. This stuff is serious – and there’s nothing easy about it.

In 2016 the National Institute on Deafness and Other Communication Disorders reported that 7.7% of American children have been diagnosed with a speech or swallowing disorder. That comes out to nearly one in 12 children, and gets even bigger if you factor in adults.

Whether rooted in psycho-speech behavioral issues, muscular disorders, or brain damage, nearly all the diagnoses SLPs make fall within just 10 common categories…

Types of Speech Disorders & Impediments

1. Apraxia of Speech (AOS)

   Apraxia of Speech (AOS) happens when the neural pathway between the brain and a person’s speech function (speech muscles) is lost or obscured. The person knows what they want to say – they can even write what they want to say on paper – however the brain is unable to send the correct messages so that speech muscles can articulate what they want to say, even though the speech muscles themselves work just fine. Many SLPs specialize in the treatment of Apraxia.

   There are different levels of severity of AOS, ranging from mostly functional, to speech that is incoherent. And right now we know for certain it can be caused by brain damage, such as in an adult who has a stroke. This is called Acquired AOS.

   However the scientific and medical community has been unable to detect brain damage – or even differences – in children who are born with this disorder, making the causes of Childhood AOS somewhat of a mystery. There is often a correlation present, with close family members suffering from learning or communication disorders, suggesting there may be a genetic link.

   Mild cases might be harder to diagnose, especially in children where multiple unknown speech disorders may be present. Symptoms of mild forms of AOS are shared by a range of different speech disorders, and include mispronunciation of words and irregularities in tone, rhythm, or emphasis (prosody).

   Severe cases are more easily diagnosed, with symptoms including inability to articulate words, groping for sound positions, off-target movements that distort sounds, and inconsistency in pronunciation.

2. Stuttering – Stammering

   Stuttering, also referred to as stammering, is so common that everyone knows what it sounds like and can easily recognize it. Everyone has probably had moments of stuttering at least once in their life. The National Institute on Deafness and Other Communication Disorders estimates that three million Americans stutter, and reports that of the up-to-10-percent of children who do stutter, three-quarters of them will outgrow it. It should not be confused with cluttering.

   Most people don’t know that stuttering can also include non-verbal involuntary or semi-voluntary actions like blinking or abdominal tensing (tics). Speech language pathologists are trained to look for all the symptoms of stuttering, especially the non-verbal ones, and that is why an SLP is qualified to make a stuttering diagnosis.

   The earliest this fluency disorder can become apparent is when a child is learning to talk. It may also surface later during childhood. Rarely if ever has it developed in adults, although many adults have kept a stutter from childhood.

   Stuttering only becomes a problem when it has an impact on daily activities, or when it causes concern to parents or the child suffering from it. In some people, a stutter is triggered by certain events like talking on the phone. When people start to avoid specific activities so as not to trigger their stutter, this is a sure sign that the stutter has reached the level of a speech disorder.

   The causes of stuttering are mostly a mystery. There is a correlation with family history indicating a genetic link. Another theory is that a stutter is a form of involuntary or semi-voluntary tic. Most studies of stuttering agree there are many factors involved.

   Because the causes of stuttering are largely unknown the treatments are mostly behavioral. Triggers often precede a stuttering episode, and SLPs can help people recognize and cope with these triggers ahead of time.

3. Dysarthria

   Dysarthria is a symptom of nerve or muscle damage. It manifests itself as slurred speech, slowed speech, limited tongue, jaw, or lip movement, abnormal rhythm and pitch when speaking, changes in voice quality, difficulty articulating, labored speech, and other related symptoms.

   It is caused by muscle damage, or nerve damage to the muscles involved in the process of speaking such as the diaphragm, lips, tongue, and vocal chords.

   Because it is a symptom of nerve and/or muscle damage it can be caused by a wide range of phenomena that affect people of all ages. This can start during development in the womb or shortly after birth as a result of conditions like muscular dystrophy and cerebral palsy. In adults some of the most common causes of dysarthria are stroke, tumors, and MS.

   As an SLP there’s not much you can do about muscle damage, and even less you can do about nerve damage. So for treatments you’ll focus on managing the dysarthria symptoms through behavior changes. This can include helping a person slow down when they’re speaking, breath training, and exercising the muscles that are involved in speech.

4. Lisping

   A lay term, lisping can be recognized by anyone and is very common.

   Speech language pathologists provide an extra level of expertise when treating patients with lisping disorders. They can make sure that a lisp is not being confused with another type of disorder such as apraxia, aphasia, impaired development of expressive language, or a speech impediment caused by hearing loss.

   SLPs are also important in distinguishing between the five different types of lisps. Most laypersons can usually pick out the most common type, the interdental/dentalised lisp. This is when a speaker makes a “th” sound when trying to make the “s” sound. It is caused by the tongue reaching past or touching the front teeth.

   Because lisps are functional speech disorders, SLPs can play a huge role in correcting these with results often being a complete elimination of the lisp. Treatment is particularly effective when implemented early, although adults can also benefit.

   Experts recommend professional SLP intervention if a child has reached the age of four and still has an interdental/dentalised lisp. SLP intervention is recommended as soon as possible for all other types of lisps. Treatment includes pronunciation and annunciation coaching, re-teaching how a sound or word is supposed to be pronounced, practice in front of a mirror, and speech-muscle strengthening that can be as simple as drinking out of a straw.

   Lisps usually develop during childhood, and children will often outgrow an interdental or dentalised lisp on their own.

5. Spasmodic Dysphonia

   Spasmodic Dysphonia (SD) is a chronic long-term disorder that affects the voice. It is characterized by a spasming of the vocal chords when a person attempts to speak and results in a voice that can be described as shaky, hoarse, groaning, tight, or jittery. It can cause the emphasis of speech to vary considerably. Many SLPs specialize in the treatment of Spasmodic Dysphonia.

   SLPs will most often encounter this disorder in adults, with the first symptoms usually occurring between the ages of 30 and 50. It can be caused by a range of things mostly related to aging, such as nervous system changes and muscle tone disorders.

   It’s difficult to isolate vocal chord spasms as being responsible for a shaky or trembly voice, so diagnosing SD is a team effort for SLPs that also involves an ear, nose, and throat doctor (otolaryngologist) and a neurologist.

   After diagnosis SLPs can have a role helping with coaching to optimize voice production, and can be particularly effective in mild cases of SD. This especially includes working on breathing control techniques to maintain a stead flow of air from the lungs.

6. Cluttering

   Have you ever heard people talking about how they are smart but also nervous in large groups of people, and then self-diagnose themselves as having Asperger’s? You might have heard a similar lay diagnosis for cluttering. This is an indication of how common this disorder is as well as how crucial SLPs are in making a proper cluttering diagnosis.

   A fluency disorder, cluttering is characterized by a person’s speech being too rapid, too jerky, or both. To qualify as cluttering, the person’s speech must also have excessive amounts of “well,” “um,” “like,” “hmm,” or “so,” (speech disfluencies), an excessive exclusion or collapsing of syllables, or abnormal syllable stresses or rhythms.

   The first symptoms of this disorder appear in childhood. Like other fluency disorders, SLPs can have a huge impact on improving or eliminating cluttering. Intervention is most effective early on in life, however adults can also benefit from working with an SLP.

   Treatment methods include delayed audio feedback, syllable articulation and annunciation coaching, playing games that involve rapid word retrieval, practicing pausing and phrasing in sentences, and increasing a clutterer’s own self-awareness of what they are doing, such as through video recording.

7. Muteness – Selective Mutism

   There are different kinds of mutism, and here we are talking about selective mutism. This used to be called elective mutism to emphasize its difference from disorders that caused mutism through damage to, or irregularities in, the speech process.

   Selective mutism is when a person does not speak in some or most situations, however that person is physically capable of speaking. It most often occurs in children, and is commonly exemplified by a child speaking at home but not at school.

   Selective mutism is related to psychology. It appears in children who are very shy, who have an anxiety disorder, or who are going through a period of social withdrawal or isolation. These psychological factors have their own origins and should be dealt with through counseling or another type of psychological intervention.

   Diagnosing selective mutism involves a team of professionals including SLPs, pediatricians, psychologists, and psychiatrists. SLPs play an important role in this process because there are speech language disorders that can have the same effect as selective muteness – stuttering, aphasia, apraxia of speech, or dysarthria – and it’s important to eliminate these as possibilities.

   And just because selective mutism is primarily a psychological phenomenon, that doesn’t mean SLPs can’t do anything. Quite the contrary.

   SLPs can play an important role through working with selectively mute children to create a tailored behavioral treatment program and address speech and language disorders – such as stuttering – that may be contributing to psychological factors like excessive shyness.

8. Aphasia

   The National Institute on Neurological Disorders and Stroke estimates that one million Americans have some form of aphasia.

   Aphasia is a communication disorder caused by damage to the brain’s language capabilities. Aphasia differs from apraxia of speech and dysarthria in that it solely pertains to the brain’s speech and language center.

   As such anyone can suffer from aphasia because brain damage can be caused by a number of factors. However SLPs are most likely to encounter aphasia in adults, especially those who have had a stroke. Other common causes of aphasia are brain tumors, traumatic brain injuries, and degenerative brain diseases.

   In addition to neurologists, speech language pathologists have an important role in diagnosing aphasia. As an SLP you’ll assess factors such as a person’s reading and writing, functional communication, auditory comprehension, and verbal expression.

   Because the field of brain damage repair is in its infancy, your role as an SLP is to help with coping methods and strategies. The brain is a remarkable organ, and sometimes when one part gets damaged another part will try and pick up the slack. That means you can also try working on activities to improve the language skills that have been affected by the brain damage – sometimes this can have an effect.

9. Speech Delay – Alalia

   A speech delay, known to professionals as alalia, refers to the phenomenon when a child is not making normal attempts to verbally communicate. There can be a number of factors causing this to happen, and that’s why it’s critical for a speech language pathologist to be involved.

   The are many potential reasons why a child would not be using age-appropriate communication. These can range anywhere from the child being a “late bloomer” – the child just takes a bit longer than average to speak – to the child having brain damage. It is the role of an SLP to go through a process of elimination, evaluating each possibility that could cause a speech delay, until an explanation is found.

   Approaching a child with a speech delay starts by distinguishing among the two main categories an SLP will evaluate: speech and language.

   Speech has a lot to do with the organs of speech – the tongue, mouth, and vocal chords – as well as the muscles and nerves that connect them with the brain. Disorders like apraxia of speech and dysarthria are two examples that affect the nerve connections and organs of speech. Other examples in this category could include a cleft palette or even hearing loss.

   The other major category SLPs will evaluate is language. This relates more to the brain and can be affected by brain damage or developmental disorders like autism. There are many different types of brain damage that each manifest themselves differently, as well as developmental disorders, and the SLP will make evaluations for everything.

   Once the cause or causes for the speech delay are identified then the SLP can go to work treating and monitoring the child. For many speech-language disorders that cause a speech delay, early intervention and evaluation by an SLP can make a huge difference.

10. Issues Related to Autism

    While the autism spectrum itself isn’t a speech disorder, it makes this list because the two go hand-in-hand more often than not.

    The Centers for Disease Control and Prevention (CDC) reports that one out of every 68 children in our country have an autism spectrum disorder. And by definition, all children who have autism also have social communication problems.

    Speech-language pathologists are often a critical voice on a team of professionals – also including pediatricians, occupational therapists, neurologists, developmental specialists, and physical therapists – who make an autism spectrum diagnosis.

    In fact, the American Speech-Language Hearing Association reports that problems with communication are the first detectable signs of autism. That is why language disorders – specifically disordered verbal and nonverbal communication – are one of the primary diagnostic criteria for autism.

    So what kinds of SLP disorders are you likely to encounter with someone on the autism spectrum?

    A big one is apraxia of speech. A study that came out of Penn State in 2015 found that 64 percent of children who were diagnosed with autism also had childhood apraxia of speech.

    A study published in the National Center for Biotechnology Information out of Harvard Medical School cites muteness, involuntarily repetition of another person’s vocalizations (echolalia), and unusual inflection and tone (prosody) as also being characteristics of people on the autism spectrum, especially children. It points out that in general language abilities are impaired or delayed at an early age.

This basic primer on the most common speech disorders offers little more than an interesting glimpse into the kind of issues that SLPs work with patients to resolve. But even knowing everything there is to know about communication science and speech disorders doesn’t tell the whole story of what this profession is all about. With every client in every therapy session, the goal is always to have the folks that come to you for help leave with a little more confidence than when they walked in the door that day. As a trusted SLP, you will build on those gains with every session, helping clients experience the joy and freedom that comes with the ability to express themselves freely. At the end of the day, this is what being an SLP is all about.

Ready to make a difference in speech pathology? Learn how to become a Speech-Language Pathologist today