Type I is considered the most common. Stress leads to a locking of the vocal cords which shortly precedes the stutter which coincides in time with speech. The struggle with speech consists of hesitations, repetitions and prolongations of sounds, syllables or words. When the average non-stuttering individual thinks of stuttering, it is Type I he has in mind.

The second category is Type II. Again stress leads to the locking of the vocal cords which reflexively triggers a struggle, but in this instance the struggle is not part of speech but precedes it. The struggling may be violent but the stutterer has elected to delay speech until after the struggle - so the speech, when it occurs, is fluent.

Type II stutterers are fascinating to observe as they speak on the telephone. Their head may be thrust back in some violent gesture, their jaw may shake, eyes clench, hands thrust - while the person at the other end hears nothing, just a pause followed by normal-sounding speech. If the listener knew the magnitude of the titanic struggle ensuing at the other end of the line, he would be amazed and appalled.

I later treated such a stutterer in England. The day before treatment, I had arranged an appointment to meet with him at a small airport just outside of London. He was a pilot and had offered a bird's eye view of the city and surrounding countryside.

As a Type II stutterer, his speech on the radio to the tower sounded normal, but the struggle taking place in the cockpit as we taxied to the runway suggested I was about to have a bumpy ride.

And indeed it was, for his struggles involved his entire body, including both arms and legs. And each sentence that emerged fluently was preceded by a brief but hair-raising form of aerial aerobatics that left my at the end of the flight exhausted and air-sick.

We had arranged that he would drive me back to London. The trip took about an hour and I recall speaking almost incessantly, since whenever he spoke, the car lurched.

The Type II stutterer demonstrates that the struggle to release the vocal cord spasm is clearly independent of speech. The fact that for most stutterers the struggle appears in the speech (Type I) is simply an expression of their inability to wait and complete their struggles before starting to speak.

In Type III stuttering the stress also provokes the locking of the vocal cords, but the patient has elected not to struggle but to pause and wait until the locked cords release. This may be accomplished by several means: he may distract himself in some appropriate manner, he may passively wait for his stress to drop, he may quietly inhale to open his vocal cords, or he may swallow to achieve the same end. One patient I treated would cough gently during such pauses to blow his vocal cords apart.

Another patient would pause, smile, look up at the ceiling and appear to be deep in thought before responding. If one looked closely at his Adam's Apple, however, one observed that it bobbed up and down very rapidly during these "reflective" pauses. What the patient was actually engaged in was a series of very rapid swallows to open his vocal cords. If a single swallow was sufficient the pause would be brief. But if his cords locked again too quickly, it might be necessary to swallow two, three or four times in quick succession to speak.

Beneath the smile, and apparent thoughtfulness, lay a violent, hidden and single-minded struggle to deal with a spasm that both blocked breathing and speech.

Finally, in Type IV stuttering the stuttering chain is aborted before it starts. The stutterer uses an avoidance behavior when his conscious habit of scanning informs him of the presence of "trouble ahead."

This type is referred to as the hidden or "closet" stutterer (discussed in the next chapter). Twenty percent of all patients seen at the National Center for Stuttering fit this category. These patients avoid words, sounds, and speaking situations. No one knows they stutter, but the price they pay for their fluency is constant vigilance.

Type I stuttering is the "typical" form, seen most often in stutterers. The struggles are part of speech. Type II stuttering, though less frequent, is also recognized as stuttering even though the speech is unimpaired. Type III and Type IV stuttering are socially acceptable; they are not recognized as forms of stuttering. Stutterers in these two categories rarely seek professional help even though these forms of the disorder often take a considerable emotional toll.

As I examined more and more adult stutterers, I was to discover mixtures of each of the four types. For example, a patient might struggle with the pronunciation of his name, substitute one word for another while describing his occupation, and cough to release his laryngeal spasm before describing an experience. I was to discover that a mixture of types within patients was the rule rather than the exception. There were, of course, "pure" types, and clinicians would see them on occasion. They were mostly Type I and Type II. Types III and IV were rarely seen, not because they did not exist in substantial numbers, but rather because they did not seek assistance.