Differences in blocking?

Differences in blocking? You guys are most likely familiar with the Valsalva Control Therapy by William D. Parry but one thing that kind of confuses me is that he keeps on talking about ''blocking'' while in reality he is actually talking about prolonging words as in p-p-p-peter. I thought blocking is like not being able to produce a sound at all so basically being silent for 5 seconds and then pushing the word out. So is my definition of a speech block wrong or can you use it in both ways?