Color Breathing- Weird Sound

Hey all, I was just listening to threshold 4- Color Breathing, and 2 times during the exercise I heard a sudden and abrupt static noise that interrupted any other sound. Im not sure when the first one i heard was, but when the second one went off I paused and noted the time into the exercise, 20:17, and what he was saying, "...Have available to your conscious self, the benefits and values of such (static noise) experience...". I was just wondering what that noise was all about and if i've got a broken copy or something like that. Any insights on the matter would help (^_^) thanks.