Speech-language pathology is the treatment for the improvement or cure of communication disorders, including speech, language, and swallowing disorders. Speech disorders treated by speech-language pathologists include voice disorders (abnormalities in pitch, volume, vocal quality, or resonance or duration of sounds), articulation disorders (problems producing speech sounds), and fluency disorders (impairment in speech fluency, such as stuttering ). Language disorders include developmental or acquired conditions that lead to difficulties in understanding or producing language. Speech-language pathologists participate in the screening, assessment, and treatment of patients who experience one or a combination of these disorders.