Focus on the Treatment Team: Speech-Language Therapy

This month’s ASAT feature comes to us from Kate McKenna, MEd, MSEd, MS, BCBA, and Lindsay Bly, MS, CCC-SLP, Melmark. To learn more about ASAT, please visit their website at You can also sign up for ASAT’s free newsletter, Science in Autism Treatment, and like them on Facebook!

This is part of the Description of the Treatment Team series.


The science of speech-language pathology in the United States had its roots in the study of elocution, what we now call articulation, for rhetoric debate, and theatre, which had risen to prominence in 18th century England. Several clinicians of the era (e.g., Potter) that were considered legitimate came from the profession of education, medicine, and elocution. With the publication of Speech and its defects. Considered physiologically, pathologically, historically, and remedially (Potter, 1882), the field expanded to include speech and language disorders. Potter provided a taxonomy of all speech disorders and a definition and suggested treatments for each. This publication then became the model for the field of speech-pathology in the early period in its history. Speech production continued to be the primary focus of the field in the United States as reflected by the establishment of the American Academy of Speech Correction, in 1925 at a meeting of the National Association of Teachers of Speech (NATS), held in New York City, whose members wanted to promote “scientific, organized work in the field of speech correction.” ( The establishment of the Academy was the birth of American Speech-Language Hearing Association (ASHA).

As an organization the Academy has gone through several name changes and in 1978 took its current title of the American Speech-Language Hearing Association (ASHA). The organization that began with 25 charter members now represents over 228,000 speech-language pathologists. Based in Rockville, Maryland, ASHA is committed to a mission of empowering and supporting audiologists, speech-language pathologists, and speech, language, and hearing scientists.

As with the professions of physical and occupational therapy, injuries in the World Wars also spurred growth and diversification in the field of speech and language therapy. Soldiers returning from the battlefields had suffered brain injuries that resulted in aphasia, a language disorder that involves loss of the ability to understand or express speech and language. Consequently, during the 1940’s and ’50s, as brain studies, technological advances, and the development of standardized testing procedures gave rise to more useful receptive and expressive language assessments and treatment techniques, speech therapists began to expand their focus into the treatment of language disorders. The field of speech pathology became speech-language pathology during this time.

Although speech and language disorders can occur by themselves, they often exist together, which is why speech-language pathology is a combined field of study. During the 1960’s through the ’80’s, advances in linguistic studies further enhanced the speech-language pathologist’s understanding and ability to treat a variety of language delays and disorders in persons of any age. In the 21st century, speech-language pathologists have begun to research and treat the pragmatic use of language along with the other areas of communication disorders.

Today’s speech-language pathologist is a professional whose professional practice and expertise is in diagnosis, screening, assessment, and treatment of challenges and difficulties, in the areas of communication, including speech, language, cognition, voice, fluency, resonance and hearing, and swallowing in people of all ages. Moreover, SLPs practice within eight domains of speech-language pathology service delivery: collaboration; counseling; prevention and wellness; screening; assessment; treatment; modalities, technology, and instrumentation; and population and systems. In addition, SLPs engage in five domains of professional practice including: advocacy and outreach, supervision, education, research, and administration/leadership. A speech disorder is identified as when someone has a hard time producing speech sounds and misarticulations, has a voice problem, or stutters when speaking. A language disorder is when an individual experiences difficulties understanding and using language to communicate, sharing their thoughts and emotions, and engaging in conversation with others as a conversational partner.


The education and training of speech-language pathologists is overseen by the Council on Academic Accreditation in Audiology and Speech-Language Pathology (CAA), which is an entity within the American Speech-Language-Hearing Association (ASHA). ASHA is the national professional, scientific, and credentialing association of speech-language pathologists and audiologists. According to ASHA, to practice as a speech-language pathologist (SLP), a masters, doctoral, or other recognized postbaccalaureate degree from a CAA accredited program is required along with completing 400 supervised clinical hours, with at least 25 hours spent in guided observation and at least 375 hours spent in direct client/patient contact, with 325 completed at the graduate level. Supervision is required in real time and never less than 25% of the student’s total contact with each client/patient. Aspiring speech-language therapists must also pass a Praxis Exam in Speech-Language Pathology and complete a clinical fellowship of at least 36 weeks and 1260 hours of full-time experience or its part-time equivalent. During the clinical fellowship applicants are rated by their mentor according to the Clinical Fellowship Skills Inventory (CFSI), which consists of 18 skill statements covering the areas of evaluation, treatment, management, and interaction. Mentees are judged on accuracy and consistency, which assesses the performance of a skill without error, consistently across cases, as well as independence and supervisory guidance, which measure both the level of independence and the ability to self-monitor skill level and request support as necessary. After being granted a Certificate of Clinical Competency (CCC) from ASHA, speech-language pathologists are required to complete 30 hours of professional development every three years. Other license requirements vary by state.

Speech-Language Pathology Assistants (SLPA) can become certified through three different educational pathways and must complete 100 hours of clinical field work under the supervision of an SLP. In addition, applicants take courses in ethics, universal safety precautions and complete the ASHA online SLPA education modules. As with SLPs, speech-language pathology assistants pass a certification exam and renew their certification every three years.

Standards of Practice and Guiding Documents

In their practice speech-language pathologists are guided by the ASHA Code of Ethics, which reflects the values and expectations for both research and clinical practice. The code is intended to provide a framework for ethical decision-making and professional conduct. Four Principles of Ethics form the philosophical base of the Code: 1) responsibility to persons served professionally and to research participants, 2) responsibility for one’s professional competence, 3) responsibility to the public, and 4) responsibility for professional relationships. The Scope of Practice in Speech-Language Pathology also governs the practice of speech-language pathologists. This document is a framework for practice and describes the domains of service delivery. The work of speech-language pathologists assistants is guided by similar documents, a Code of Conduct, and a Scope of Practice, that describe the limits of service delivery as they work under the supervision of SLPs. A goal of SLPs is to provide evidence-based treatment and interventions to clients. To this end, ASHA has created Evidence Maps, a searchable online tool designed to assist speech-language therapists in making evidence-based decisions in their practice.

Professional Organizations

The American Speech-Language Hearing Association (ASHA), is the professional and credentialing organization for audiologists, speech-language pathologists, scientists studying speech, language and hearing, and has 20 Special Interest Groups (SIG) that indicate the breadth and depth of study in the professions. Its mission is “Making effective communication, a human right, accessible and achievable for all.”

ASHA publishes five peer-reviewed journals. American Journal of Audiology (AJA) is an online only peer-reviewed journal that publishes research and other scholarly articles pertaining to clinical audiology methods and issues. American Journal of Speech-Language Pathology (AJSLP) is an international journal that publishes clinical research on diverse aspects of clinical practice in speech-language pathology, including screening, diagnosis, and treatment of communication and swallowing disorders. Articles in the Journal of Speech, Language, and Hearing Research (JSLHR) touch on speech, language, hearing, and related areas such as cognition, oral-motor function, and swallowing. Language, Speech, and Hearing Services in Schools (LSHSS) focuses on school age children and adolescents and audiological and communication disorders that impact full participation in the school setting. Perspectives of the ASHA Special Interest Groups, a bimonthly online peer-reviewed journal, publishes research related to the 20 SIGs. The ASHA Leader, which highlights the latest research and practice advances in communication sciences and disorders, is a bimonthly newsmagazine for and about audiologists, speech-language pathologists, and speech, language, and hearing scientists available to all ASHA members.

Scope of Practice

The SLP profession falls under the larger discipline of communication sciences and disorders, which also includes audiology. Speech-language pathology is focused on a range of human communication and swallowing disorders affecting people of all ages. The practice of speech-language pathology includes those who want to learn how to communicate more effectively, such as those who want to work on accent modification or improve their communication skills. It also includes the treatment of people with tracheostomies and ventilators and those who use Augmented and Alternative Communication such as manual signs, gestures, picture or letter communication boards, and speech generating devices.

Speech is a verbal form of communication that is comprised of articulation, how speech sounds are produced (e.g., manner, placement, and voicing), voice, the coordination of the breathing/respiratory apparatus and vocal cords to produce those sounds, and fluency, the rhythm of speech. Speech problems often occur because a person has difficulty producing sounds due to difficulties or incorrect movement or development of the lips, tongue, and mouth, and/or coordination of the speech motor and respiratory mechanism. Language consists of socially shared rules that govern what words mean, how new words are created, and how words are put together in sentences. It also includes what we call the pragmatics of language, the socially accepted rules for interacting in daily life. This includes non-verbal communication (eye contact, facial expressions, body language) as well as conversational skills such as turn taking, asking questions, appropriately maintaining conversations, and adjusting language and vocabulary based on the situation. Speech-language pathologists treat both receptive (difficulty understanding others) and expressive language disorders (difficulty communicating thoughts, ideas, and feelings).

According to The American Speech-Language-Hearing Association, these are the eight domains of speech language disorder and the disorders that fall under the umbrella of speech-language pathology:

Fluency Disorders:

  • Stuttering: Interruption in the flow of speaking characterized by specific types of disfluencies.
  • Cluttering: Characterized by a perceived rapid and/or irregular speech rate, atypical pauses, maze behaviors.

Speech Production Disorder:

  • Motor planning and execution disorders:
    • Childhood speech apraxia: Neurological childhood speech sound disorder resulting from neuromuscular difficulties, such as abnormal reflexes or abnormal tone.
    • Adult speech apraxia: Speech disorder caused by neuromuscular difficulties, such as abnormal reflexes or abnormal tone; usually because of stroke, traumatic brain injury, dementia, or other progressive neurological disorders.
  • Speech sound disorders:
    • Articulation: Errors (e.g., distortions and substitutions) in production of individual speech sound
    • Phonological: Predictable, rule-based errors (e.g., fronting, stopping, and final consonant deletion) that affect more than one sound.

Language Disorder:

  • Language disorder: A significant impairment in the acquisition and use of language across modalities due to deficits in comprehension and/or production across any of the five language domains (i.e., phonology, morphology, syntax, semantics, and pragmatics).
  • Written language disorder: A significant impairment in fluent word reading (i.e., reading decoding and sight word recognition), reading comprehension, written spelling, and/or written expression. Dyslexia – word reading disorder.
  • Areas of language include phonology, morphology, syntax, semantics, pragmatics (language use and social aspects of communication), prelinguistic communication (e.g., joint attention, intentionality, communicative signaling), paralinguistic communication (e.g., gestures, signs, body language), literacy (reading, writing, spelling)


  • Cognitive-Communication Disorders: Difficulties paying attention, planning, problem-solving, or organizing their thoughts. Many times, these disorders occur because of a traumatic brain injury, stroke, or dementia.


  • Voice disorders: Includes vocal cord nodules and polyps, vocal cord paralysis, spasmodic dysphonia, and paradoxical vocal fold movement.
  • Dysarthria: Impaired movement of the muscles used for speech production, including the vocal cords, tongue, lips, and/or diaphragm.

Resonance Disorder:

  • Resonance disorders: Too much or too little nasal and/or oral sound energy in the speech signal.

Feeding and Swallowing:

  • Swallowing Disorders: Difficulty eating and swallowing. Swallowing disorders are often a result of an illness, injury, or stroke.
    • Oral phase
    • Pharyngeal phase
    • Esophageal phase
  • Atypical eating (e.g., food selectivity/refusal, negative physiologic response)

Auditory Habilitation/Rehabilitation:

  • Speech, language, communication, and listening skills impacted by hearing loss, deafness.
  • Auditory processing

SLPs practice in many settings including schools, homes, and hospitals. They also provide services to those in outpatient clinics or in long-term care facilities. In addition to working with adults with persistent speech/language needs who were diagnosed with developmental disabilities from a young age, SLPs work with people across the lifespan, providing care and treatment in early intervention to working with adults with whom a major medical event may have caused a speech or language disorder. They also work in mental and behavioral health settings. SLPs are also involved in academia and research advancing the knowledge base of the field. Given the various settings that SLPs work in, overlapping scopes of practice across health care, educational and other settings is a reality. As such, SLPs engaged in interprofessional collaborative practice to ensure that individuals served will benefit from the collaborative comprehensive approach, receive effective interventions that lead to meaningful and best health and educational outcome.

Speech-language pathologists are health care professionals who identify, assess, and treat speech, language and swallowing disorders, preventing, and treating communication disorders in people of all ages.  The principles and code of ethics that guide members of the profession highlight safeguarding human dignity, protecting the rights of individuals seeking treatment, celebrating diversity, and embracing collaboration in their efforts to ensure that the individuals with whom they work can communicate effectively.

We would like to thank Dr. Lina Slim for her contributions to this article. We appreciate her insight and expertise.


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Citation for this article:

McKenna, K., & Bly, L. (2023). Focus on the treatment team: Speech-Language Therapy. Science in Autism Treatment, 20(5).

About the Authors

Kate McKenna, MEd, MSEd, MS, BCBA, LBA, received a Masters in Child Study from the Eliot-Pearson Department of Child Study at Tufts University, a Masters in Special Education from Pace University, and a Masters in ABA from Hunter College.  In addition to New York state certifications in general and special education from Birth to Grade 2 and Grades 1-6, she holds a New York State Annotated Certification in Severe/Multiple Disabilities. Kate is currently completing a Masters degree in Children’s Literature at Eastern Michigan University.  She was an extern at the Association for Science in Autism Treatment before joining the Board of Directors in 2020.

Lindsay Bly, MS, CCC-SLP, is an ASHA certified speech language pathologist. After receiving her master’s degree at Clarion University of Pennsylvania, she began specializing in dysphagia management and augmentative and alternative communication (AAC) evaluation and implementation. In 2018, Lindsay assumed a newly created speech language pathologist position in the intermediate care facility (ICF) at Melmark. Lindsay develops, creates, and collaborates on protocols to minimize the risk of aspiration in medically complex patients with significant and multiple disabilities including a rigorous evaluation schedule and maintenance treatment for all at risk patients. Lindsay has a passion for management of oropharyngeal dysphagia and maximizing quality of life through least restrictive and safest diets.

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