1. a
needle that
acts when the
auditor speaks and does nothing the rest of the
time.
(EMD, p. 42)2. it is a total
uniform speed. There is not the faintest
tick in it. There is not the faintest speed-up. There is nothing. It is just like molasses pouring out of the barrel—and there it is, and that's a clean
needle.
(SH Spec 224, 6212C13)3. one which
flows,
producing no pattern or erratic motions of the smallest kind with the
auditor sitting looking at it and doing nothing. A clean
needle is not just something that doesn't react to a
particular question. It's a lovely slow
flow, usually a
rise, most beautifully expressed on a
Mark V at 64 sensitivity.
(HCOB 30 Dec 62)