Evening star. [volume] (Washington, D.C.) 1854-1972, 1930-07-13

boiler works, 1t Is obvious that little
could be done TO improve conditions.
And In blacksmith shop manifestly IL
would be out of the question TO use
rubber anvils. The Clash Of metal on
metal inevitably must be productive of
noise. Yet there Is one method by
which even a metal working shop can
be improved.
Experiments show that noise il mate
rally added to by reflected sounds. The
clash Of a punching machine makes a
given sound. Some portion of that
sound is thrown back into the ears OF
the workers from the walls. 1t is in
eject, an echo-an immediate echo.
Material Is now available which gives
back q minimum OF such reflected
sound
Cities Consider Noise Abatement.
Careful manufacture Of many types
OF machinery, particularly ONCE equip
ment, can reduce sound. The excel
lence Of the state Of repair in which
such machinery is kept has a great deal
to do with the resulting noise. Loose
parts which rattle and bang create
added noise Typewriters, for example.
placed on pads make less noise than
those merely resting on q wood desk
surface. Floors manufactured of sound
absorbing material will appreciably
minimize every noise in q room.
In large cities, where noise of traffic
from the streets, from factory whistles
and from the general hum and din of
human endeavor invades the windows
and distracts workers, the problem has
been solved by keeping windows closed,
their edges hitting tightly into sound
repeiling material. In such cases arti-
f1cial ventilating systems must be en-
ployed. In such metropolises as New
York, Chicago and Cleveland there are
many ofices where windows never are
opened. In rebuilding the executive
offices at the White House, following
the fire last Christmas eve, this treat
ment was given the windows.
Never before has such interest been
shown in the abatement of noise Many
interests are affected beside the uues-
ton OF personal annoyance. The Amer
lean Society Of Safety Engineers, for
example, has studied the question.
Many workers in handling machinery
may be caused to start suddenly. max
ing some involuntary movement OF a
nand. and In that instant the hand
VIII touch saw, a punch, a flying
wheel, and a disastrous accident is
caused. The noise is responsible.
Instruments Prove Damage.
Scientists have invented and used
delicate instruments to reflect the ef-
1ects OF noise upon the physical system.
some OF these experiments, made upon
sleeping persons, show that noises reach
even the unconscious sensitiveness.
There is an instrument which measures
the extent OF relaxation or of tenseness
IN sleep Here is typical record taken
from a man who fell asleep at 1890
am; The line on the chart begins TO
orl1t rapidly toward the relaxation in
olcator. At 80 motor truck passes
ana the graph line darts back toward
the tensenesS indicator. Again relaxa-
tlon sets In, but about 2:45 some one
coughs. Even that sound causes an
other jerk back. At about AIS in the
morning window slams. This causes
sharp reaction. And so on.
Although the experts find that some
persons are representative and respond
70 noises more than others, noise does
have definite effect on all. Incl.
dentally, 1t is found that automobile
norns cause much more ANNOYANCE than
radio-three times as much, in fact,
Many cities are working on the prob
lem OF noise abatement, and reduction
In preventable noises may be expected
confidently. OF course. there will Ale
ways be some extremely sensitive peo-
pie bothered by the most trifiing sound
such as the man awakened by A little
kitten entering his room. treading on
soft carpet. and who barked anprilv
at the creature, You would stamp your
feet!"