Definition reprinted with permission from Hood, Stephen B. (editor) available from Stuttering Foundation of America: [amazon 093338825X inline]
Disrhythmic phonation, identified only within words, is that kind of phonation which disturbs or distorts the so-called normal rhythm or flow of speech, and may or may not be accompanied by tension. These occur within words, rather than between words, and may be attributable to a vocalized prolongation of sound, prolongations that are audible but nonvocalized, or prolongations where there are perceptible breaks in pitch or voicing. Disrhythmic phonations may also involve changes in accent or timing which are notably unusual, or have improper stress.