Subvocalization

Speed reading "experts" recommend that you do not move your head while speed reading and, instead, move the eyes. The lips must remain still, although they can remain open or closed as an option. However, subvocalisation is the imagination of the sound of the words as you read. Speed reading "experts" generally recommend that you refrain from subvocalising as it places extra burden on the cognitive resources, thus, slowing the reading down.

Research shows this claim to be false. Subvocalising is an inherant part of reading and understanding a word, and micro-muscle tests show that subvocalising is impossible to eliminate. Experiments instructing subjects to refrain from subvocalising suggest that it makes no difference to reading speed whatsoever.