MANUAL OF ANALOGUE SOUND RESTORATION ... - British Library

knobs subjectively. He should have the courtesy first to reproduce the sound with all
known objective parameters compensated. For archival purposes, this could be the end of
the matter; but it may happen that some minor deficiencies remain which were not
apparent (or curable) to contemporary engineers, and these can next be undone. In any
event, I personally think that only when the known objective parameters have been
compensated does anyone have the moral right to fiddle subjectively - whether in an
archive, or for exploitation.
The aim of objectivity implies that we should measure what we are doing. In fact,
considerable engineering work may be needed to ensure all the apparatus is performing
to specification. I know this goes against the grain for some people, who take the view
that “the ear should be the final arbiter.” My view is that of course the ear should be the
final arbiter. But, even as a professional recording engineer deeply concerned with artistic
effects, I maintain that measurements should come first. “Understanding comes from
measurement” as physical scientists say; if we can measure something’s wrong, then
clearly it is wrong.
On numerous occasions, history has shown that listeners have perceived
something wrong before the techniques for measuring it were developed; this is bound to
continue. Unfortunately, “golden-eared” listeners are frequently people who are
technically illiterate, unable to describe the problem in terms an engineer would
understand. My personal view (which you are always free to reject if you wish), is that
measurements come first; then proper statistically-based double-blind trials with “goldeneared”
listeners to establish there is a valid basis for complaining about problems; then
only when this has been done can we reasonably research ways to cure the problem. I
certainly do not wish to discourage you from careful listening; but accurate sound
reproduction must at the very least begin with equipment whose performance measures
correctly.
On the other hand, the ear is also important in a rather coarse sense - to get us
back on the right track if we are catastrophically wrong. For example, if the tape box label
says the tape runs at 15 inches per second and the tape sounds as if it’s at double speed,
then it will probably be a fault in the documentation, not a fault in our ears!
For intermediate cases, we should be able to justify subjective decisions in objective
terms. For example, if we switch the tape reproducer to 7.5 inches per second and we
perceive music at slightly the wrong pitch, then we should proceed as follows. First we
check our own sense of pitch with a known frequency source properly calibrated. Then
we quantify the error and we seek explanations. (Was it an unreliable tape recorder? or
an historic musical instrument?) If we cannot find an explanation, we then seek
confirmatory evidence. (Is the background hum similarly pitch-shifted? Does the tape play
for the correct duration?) But, at the end of the day, if there is no objective explanation, a
sound archive must transfer the tape so that at least one copy is exactly like the original,
regardless of the evidence of our senses.
The question then arises, which subjective compensations should be done in the
environment of a sound archive? A strictly scientific approach might suggest that no such
compensations should ever be considered. But most professional audio operators are
recruited from a background which includes both the arts and the sciences. It is my
personal belief that this is only to the good, because if these elements are correctly
balanced, one doesn’t dominate over the other. But it is impossible for anyone’s artistic
expertise to stretch across the whole range of recorded sound. It may be necessary to
restrict the artistic involvement of an operator, depending upon the breadth of his
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