- Articulation: Articulation is the production of speech sounds. An articulation disorder may be characterized by substitutions, omissions, additions, or distortions of speech sounds. For example, children must produce the sound "r" in order to say the word "run" instead of "wun" or if they say "thun" instead of "sun.""
- Voice: Use of an individual's vocal folds combined with breathing in order to produce sound. A voice disorder is characterized by abnormal production and/or absence of vocal quality, pitch, loudness, resonance and/or duration. For example, a voice may sound hoarse or someone may lose his/her voice from misuse or overuse.
- Fluency: the flow of speaking. A fluency disorder involves disruption in that flow and can be characterized by a atypical (not typical) rate, rhythm, and/or repetitions of sounds/syllables/words/phrases. For example, a child who stutters exhibits a fluency disorder.
Information from this section was collected from www.ASHA.org