Stuttering affects the fluency of speech. The disorder is characterized by disruptions in the production of speech sounds, also called "disfluencies."
Cluttering is a communication disorder that affects one’s ability to convey messages to others in a clear and/or concise manner. Individuals with cluttered speech often report that their listeners have difficulty understanding them, and attribute this to factors such as their rate of speech, the clarity of their speech, and/or the organization or relevance of their message.
Some who clutter have said they’ve often received such feedback as, “Slow down!”, “Don’t mumble” or “Where did that comment come from?”.