Understand key terms and concepts in speech-language pathology. Whether you’re a seasoned clinician or just starting out, this glossary is here to support your learning and practice.
A speech sound disorder in which a child’s pronunciation of the same word changes from attempt to attempt, resulting in highly variable and unpredictable speech errors.
Intellectual disability (ID) is a developmental condition characterized by significantly below-average intellectual functioning and deficits in adaptive behaviors that emerge before age 18.
Intelligibility is the clarity of speech as perceived by a listener. SLPs aim to increase intelligibility in clients with speech sound or motor speech disorders.
A feeding tube surgically placed directly into the jejunum (middle section of the small intestine), bypassing the stomach to provide nutrition, hydration, and medication.
A communication system that uses manual signs alongside speech to support language development and comprehension, typically signing only the most important words in a sentence.
A language disorder is an impairment in the comprehension and/or use of spoken, written, or symbolic language that affects semantics, syntax, morphology, or pragmatics. It may be developmental or acquired and can impact both expressive and receptive language across modalities.
A lateral lisp is a speech error where sibilants are produced with side airflow, creating a distorted, slushy sound. It typically requires therapy, as it does not resolve developmentally.
The Lidcombe Program is a parent-administered therapy for preschool children who stutter, guided by a speech-language pathologist. Parents give positive feedback for smooth speech and gentle correction for stuttering, leading to long-term fluency gains.
“Lisp” is a lay term for a type of speech distortion affecting the sibilant sounds (typically /s/ and /z/). A person with a lisp produces these sounds with abnormal tongue placement or airflow, often resulting in a “th” sound (interdental lisp) or a lateral slurring quality (lateral lisp) instead of a clear /s/ or /z/.
Malocclusion is a misalignment of the teeth or jaws (like crooked teeth, overbite, or underbite) that can alter the shape of the oral cavity. It may contribute to speech errors such as lisps, and treatment typically involves braces and speech therapy to improve clarity.
Mixed language disorders involve impairments in both receptive and expressive language skills across vocabulary, grammar, and pragmatics. These disorders may be developmental or acquired and often require long-term, individualized intervention by SLPs.
Morphology is the study of the structure of words and how they are formed from smaller meaning-bearing units called morphemes. It examines how prefixes, suffixes, roots, and grammatical inflections combine to create words and convey meaning (e.g., understanding that “un-,” “happy,” and “-ness” form “unhappiness”).
Nasal regurgitation is when food or liquid flows into the nose during swallowing due to incomplete closure between the mouth and nasal cavity. It commonly occurs in cleft palate or velopharyngeal dysfunction and may require surgery or therapy for resolution.
The natural variation in human brain function and behavioral traits, recognizing that neurological differences are normal variations of human development rather than deficits to be fixed.
Neurogenic stuttering is acquired stuttering following neurological injury, characterized by dysfluencies across word types without adaptation effects.
A neurological disorder is a condition involving dysfunction or damage to the brain, spinal cord, or peripheral nerves, leading to motor, sensory, or cognitive impairments. These disorders can be congenital, acquired, or progressive and often impact speech, language, and swallowing.
Neuromuscular diseases are disorders that impact the nerves and muscles, often leading to weakness or dysfunction in movement and coordination. These conditions can significantly affect speech production and swallowing abilities due to impaired control of the muscles involved.
Omissions (also called deletions) are speech errors where a required sound is left out entirely. An example is saying “ca” for “cat,” omitting the final /t/ sound.
Organic speech sound disorders are impairments in speech production caused by identifiable structural, neurological, or sensory abnormalities. They differ from functional speech sound disorders by having a known medical or physiological cause.
Oropharyngeal Dysphagia is a swallowing disorder marked by difficulty chewing, forming, or moving the food bolus efficiently within the mouth prior to swallowing.
Palatoplasty is the surgical repair of a cleft palate, where the split in the roof of the mouth is closed so that the mouth and nose are separated. This surgery, usually done within the first year of life, helps the child feed and speak more normally by enabling the soft palate to close off the nose during swallowing and speech.
Palilalia is the compulsive repetition of a speaker’s own words or phrases. It is linked to neurological conditions and may affect fluency and clarity.
Specialized medical care focused on providing relief from symptoms and stress of serious illness, where SLPs play a role in communication and swallowing quality of life.
Parkinson’s Disease is a degenerative brain disorder that primarily affects motor control, causing symptoms like tremors, stiffness, and slowed movement.
A swallowing disorder in infants and children that affects one or more phases of the swallowing process—oral preparatory, oral, pharyngeal, or esophageal. It involves difficulties not only with the physical act of swallowing but also with feeding behaviors, and can stem from a wide array of developmental, structural, or medical causes.
Pediatric Feeding Disorder (PFD) is a condition characterized by impaired oral intake that is not developmentally appropriate and involves one or more domains of dysfunction: medical, nutritional, feeding skill, or psychosocial. It often presents as extreme food selectivity, aversion, or refusal and requires interdisciplinary evaluation and management to support growth, nutrition, and mealtime functioning.
Phonemes are the smallest units of sound in a language that can distinguish meaning between words. For example, the words “pat” and “bat” differ by one phoneme (/p/ vs /b/), and this single sound change alters the word’s meaning.
Phonological disorders are speech sound disorders in which a child has difficulty understanding and applying the sound system of a language. Unlike articulation disorders, which are motor-based and involve incorrect sound production, phonemic disorders occur at the linguistic level.
Pitch is the perceived highness or lowness (frequency) of voice determined by vocal fold vibration. SLPs address pitch abnormalities in voice therapy and gender-affirming care.
Pragmatics is the aspect of language concerned with the use of language in social contexts – essentially, it governs how we choose our words and convey meaning in real-world interactions. It includes rules for conversation (like taking turns, maintaining topics, and using language politely or appropriately for a given situation).
Receptive language is the comprehension aspect of communication – the ability to understand what others say or what one reads. It involves processing words, sentences, and meaning, and a deficit in receptive language can result in misunderstanding messages or an inability to follow along in conversation, even if hearing is normal.
Receptive Language Disorder is characterized by significant difficulty in understanding spoken, signed, or written language, despite adequate hearing and intelligence. Affected individuals may struggle to follow directions, comprehend questions, or interpret vocabulary and syntax.