Fluency can be described as the flow and rhythm of speech. An interruption in the smooth, forward flow of speech characterized by sound or syllable repetitions (e.g., t-t-t-t-toy), sound prolongations (e.g., mmmmm-mommy), or blocks on a sound or syllable in which both the airflow and movement of the speech mechanism are stopped (e.g., b-----oy) may be considered stuttering.