Ironically, the very behaviors the individual uses to minimize the stuttering end up making it more abnormal and distracting. Covert features of stuttering Core behaviors and secondary behaviors of stuttering are visible and audible, making them relatively easy to witness and to measure. People who stutter often experience some internal phenomena that are not visible or audible to listeners and that cannot be easily measured. Most of these covert features of stuttering are emotions. Before a moment of stuttering, most people who stutter report feeling fear .
Fear is the expectation of something unpleasant and threatening.
They may fear the loss of control or may fear the penalty that they expect from their listener. These fears can become attached to specific sounds or words, to situations, such as the telephone, or to people. During a moment of stuttering, many people who stutter report feeling confusion or mental blankness. They may not be able to see a visual stimulus, such as a flashing light, or hear an auditory stimulus, such as a beeping noise, or they may have difficulty judging the passage of time. When asked how long they thought a moment of stuttering was immediately after the moment, most people who stutter perceived the moment as longer in duration than it actually was.