According to the National Institute on Deafness and Other Communication Disorders (NIDCD):
Speech and language disorders affect one’s ability to speak, understand, read, and write. These disorders have a variety of causes and may range from a single phoneme speech sound error to a total loss of the ability to understand or use speech and language to communicate effectively.
Children who have trouble understanding what others say (receptive language) or difficulty sharing their thoughts (expressive language) may have a language disorder. Specific language impairment (SLI) is a language disorder that results in a delay of the mastery of language skills. Some children with SLI may not begin to talk until their third or fourth year.
Children who have trouble producing speech sounds correctly, who use an atypical vocal pitch or quality, or who hesitate or stutter when talking may have a speech disorder. Apraxia of Speech is a motor speech disorder that makes it difficult to put sounds and syllables together in the correct order to form words.
Preschoolers often have problems with pronunciation and difficulties putting sentences together. Consonant blends, where two consonants are right next to each other, are typically difficult for them. 3-year-olds often mix up multi-syllabic words or reduce them to shorter words. All of these mispronunciations are common up until age 6. Just be sure your preschooler’s speech is improving over time. By age 3, most of what your child says should be pretty understandable. However, if your child isn’t talking or is talking very little, you should act more quickly. Rule out a hearing problem first.
Talk to your child’s doctor if you have any concerns. Their doctor may refer you to a speech-language pathologist, who is a health professional trained to evaluate and treat people with speech and/or language disorders. The speech-language pathologist will discuss your child’s communication and general development with you to determine risk-factors and to hear about your specific observations. He or she will also use diagnostic assessments to evaluate your child.
The role of a Speech Language Pathologist is to evaluate, diagnose and treat children and adults with the following communication disorders:
Aphasia
Articulation and Phonological Delay or Disorder
Augmentative/Alternative Communication
Autism Spectrum Disorders
Cognitive Communication Disorders
Developmental Delay or Disability
Executive Functioning Disorders
Fluency Disorders
Language Impairment
Motor Speech Disorders
Pragmatics or Social Communication Disorders
Literacy
Swallowing Disorders
Traumatic Brain Injury
Voice and Resonance Disorders
Speech-language Pathologists select intervention approaches in order to:
Through the American Speech-Language-Hearing Association (ASHA), SLPs can join one, or more, of the following areas, called Special Interest Groups (SIGs):
SIG 1: Language Learning and Education
SIG 2: Neurophysiology and Neurogenic Speech and Language Disorders
SIG 3: Voice and Voice Disorders
SIG 4: Fluency and Fluency Disorders
SIG 5: Speech Science and Orofacial Disorders
SIG 6: Hearing and Hearing Disorders: Research and Diagnostics
SIG 7: Aural Rehabilitation and Its Instrumentation
SIG 8: Public Health Issues Related to Hearing and Balance
SIG 9: Hearing and hearing Disorders in Childhood
SIG 10: Issues in Higher Education
SIG 11: Administration and Supervision
SIG 12: Augmentative and Alternative Communication
SIG 13: Swallowing and Swallowing Disorders (Dysphagia)
SIG 14: Communication Disorders and Sciences in Culturally and Linguistically Diverse (CLD) Populations
SIG 15: Gerontology
SIG 16: School-Based Issues
SIG 17: GLobal Issues in Communication Sciences and Related Disorders.
SIG 18: Telepractice