"Talk, talk, talk!" says Alan Turing, imitating the squawk of furious hens. The strange noise is made stranger by the fact that he is wearing a gas mask, until he becomes impatient and pulls it up onto his forehead. "They love to hear themselves talk." He is referring to Winston Churchill and Franklin Roosevelt. "And they don’t mind hearing each other talk—up to a point, at least. But voice is a terribly redundant channel of information, compared to printed text. If you take text and run it through an Enigma—which is really not all that complicated—the familiar patterns in the text, such as the preponderance of the letter E, become nearly undetectable." Then he pulls the gas mask back over his face in order to emphasize the following point: "But you can warp and permute voice in the most fiendish ways imaginable and it will still be perfectly intelligible to a listener." Alan then suffers a sneezing fit that threatens to burst the khaki straps around his head.