Research shows that, although people who clutter are often less intelligible (caused by a too fast speech), they are able to produce correct syllable and word structures in some situations. This all has to do with their so-called speech motor control, which should be appropriate to speak fluently. Some researchers describe speech motor control as the ability to time articulatory, respiratory and laryngeal movements, that lead to fast and accurate syllable production. In cluttering speech motor control at word level is disturbed in high speech rate, which results in word structure errors. In other words, when clutterers lower their speech rate well enough, these word structure errors disappear.