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Old November 12th 03, 02:21 PM
M. J. Powell
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In message , MichaelJP


I have to agree - only with modern DSP "anti-noise" technology could you
have filtered out all the engine noise.

Maybe a recording was attempted, found to be unuseable, and the resulting
script was then re-recorded in the studio. I don't think this was an attempt
to deceive though, just common practice at the time, as per Churchill's

I put these points to a B/C ng group and several interesting points

One poster said.


Lip ribbon mics were first developed in 1937, so presumably they would
have been available for this application in the war. Not only is the
ribbon just 6cm or so from the speaker's mouth, but they have
considerable LF cutoff to counter the proximity effect. This would have
greatly reduced the very deep engine noise of a Lanc.

AIUI, aircraft comms of the day used carbon mic inserts.

The reported uselessness of the intercom does not necessarily mean that
the intercom's mics were overwhelmed with engine noise. It might have
been that the overwhelming occurred between the earphones and the ear.
This seems plausible, because the SPL of speech is much higher in front
of the speaker's mouth than adjacent to the listener's ear.

A day or two ago there was something on the telly - I can't for the life
of me remember what - in which the presenter was doing a piece to camera
in a light aircraft using a lip ribbon mic. There was very little
background noise audible.

I once did a radio interview with someone while standing next to the
main engines in a cross-channel ferry. (They have cylinders the size of
dustbins.) We were both wearing ear defenders, and had to lip read to
communicate with each other, but the speech on the recording - made
using an omni mic very close up - was perfectly intelligible. The
background noise on the tape was considerable, but the engines were
bigger and closer than those on a Lancaster bomber, and we didn't use a
lip ribbon mic.

It's also interesting to note that in the recording which contains
machine gun fire, as the Lanc shoots down a German fighter, that gunfire
is much louder than the engine noise.

On this basis, I think the Wynford V-T recording could perfectly well be


He raises several very good points here, I believe.