Out along the freeway they're erecting these bloody great wooden
walls, 4 to 5 metres high, accoustic barriers to cut down on the road
noise that permeates the surrounding suburbs. In a trial, the
university checks out the noise-attenuating properties of the walls,
placing microphones in strategic places, etc., all according to the
rules for a proper, scientific, experiment.
Zilch, is the answer. The walls have no sound-deadening effect in the
houses and backyards, zero, none whatsoever. Indeed, where the walls
curve around corners, there are places the road noise is actually
amplified.
But the residents love the barriers. 'Up goes a wall,' they say, 'and
down goes the traffic noise. We can tell. We live here, and that is
our experience. Reduced accoustic pollution.' The wall-building
program goes on, costing millions. The residents adore their new
'quiet', swear by it. The accoustic scientists pack their equipment
and charts, slink back to the campus.
Human perception is the instrument we rely on to secure recognition,
recognition, for example, that an event in the sequence is
sufficiently abnormal to signify that the 'error chain' has taken
charge. Yet we know the measuring instrument is totally unreliable.
How can we, then, claim to use it - judgement - to enhance safety?
Calibrate it. I know the mechanism that distorts judgement, in these
matters. I learned that through practice. I can lead other pilots
through the same exercises, letting them discover their own
'recognition-blocking' tendency. It's all done, in vitro, in an
empirical environment. You replicate key sensations so that they can
be observed in such a way as to supply the learning experience. And it
works. If people learn, through such real, personal, experience, the
influences that corrupt their perception, they enhance accuracy and
reliability factors in their judgement. They improve recognition.
Late night in the Southern ocean, mid-winter, the DDG is pitching and
rolling, it's freezing cold in the ward room, this is no place for a
sensitive Air Force pilot! (They don't even have proper beds on this
tub!) Salvation exists in the form of an artificial fireplace nestled
in the wall. We huddle around it, hands stretched out to the warmth. A
pile of plastic 'coals' glows in the grate of this life-saving piece
of kitsch.
One of the Navy officers leans forward, flicks a switch. The coals
die. Instant chill! I snarl through chattering teeth, 'Turn the bloody
thing back on.' They all fall around laughing, him and the other naval
blokes. 'Idiots!' I think, 'The terrible legacy of recruitment from
amongst the lower classes.' Later, they point out that the heat source
is actually a three-bar radiator below the 'fire', that the switch
merely turned off the light bulb behind the 'coals', took out the
visuals, so to speak, the heat having remained on throughout. Sure
fooled me.
Good experience, though. You can only learn about the things that go
wrong with our judgement through experience. Talking about it, hearing
about it, watching videos, none of that will do it. You must
experience it, in a controlled environment, with the 'background
noise' of familiarity and old habits tuned all the way down.
'Enhance accuracy and reliability factors in judgement'. Isn't that
what we are trying for? Exposure to training like this is damned
uncomfortable, hence its lack of popularity. But it must be done.
So much for 'recognize'. I'll leave 'respond' to you, Vince.
Cheers
Doug