Evening star. [volume] (Washington, D.C.) 1854-1972, 1930-10-12
CITY NOISES
BY FREDERIC ]. HASKIN.

w. wynne, the commissioner Of health,
are well pleased with the progress that
has been made. Residents OF New York
and visitors to the metropolis may be
unable rs yet TO believe that the city 10
materially auieter than 1t was year
ago. but that it is said, is because the
volume of noise by day and by might
was so great that anything short OF q
so per cent reduction could not be
noted save by experts.
A QUESTIONABLE to determine what
kind Of noises annoyed New Workers
showed that 1928 per cent Of the COM
plants were against trafiic noises, 1879
1894 per cent against radios, 9.23 per
cent against the noise made in colec-
lions and deliveries, 8.2S against whistles
and bells, IA per cent against pneu-
matte drills and riveterS and other con-
struction noises, 1877 per cent against
newsboys, peddlers, dogs, cats and Wild
parties and 2.89 per cent against noises
from miscellaneous sources.
How Noise Is Measured.
A travelling noise laboratory cruised
Greater New York under the direction
of the Noise Abatement Commission. 1t
was manned by trained technical men
and observers and fitted With noise
measuring devices of two types-one
that measured the deafening effects OF
noise and the other, called noise
meter. that picked up the noise direct
~ through microphone and registered
its intensity on dial. The unit OF
loudness used was the decibel, which
has been described approximately as
the smallest change which the ear can
detect in the level OF sound.
More accurately, the unit may be de-
fined as the ratio of intensities. Thus
II the intensitieS Of two sounds are In
the ratio Of 10 to /, they differ by 10
nicalities of the processes by which 1t
arrived at its conclusions, it may be
said that the commission found, for
example, that the clatter of rtveting
and the roar Of blasting in subway ex-
cavations are almost 10000 900
times as intense as the smallest sound
that can be distinguished by the hui
man ear.
The blast Of steamship whistle II
exceeded by the average noise Of sub.
way express as 1t passes aNlocal station
underground. A steam operated pile
driver and subway local observed un-
derground make noises that have an
intensity about ,000,000,000 times the
smallest sound that can be heard.
The loud speaker, measured In Radio
Row. where 1t is at its worst, has an
INTENSITY ABOUT 1UU,UUU,UUu VlIIlSo
greater than the smallest distinguish
able sound, and what were classed as
proportionately quiet" notes.-the ex-
haust from unmuffled motor trucks.
subway noises as perceived on the
street through q grating, a street car
passing over q crossing In the tracks,
squeaking automobile brakes and auto
mobile horns, and the regular standard
din Of street trafic-were found to
have intensities that ranged from a
million to q hundred million times
the intensity Of sound at the thresh-
old Of hearing.
To make comparisons on Q basis
everybody will understand It may be
said that although roaring lion would
be audible In New York streets at Q
distance Of 90 to 80 feet, there are
many places where tiger from Siberia
or Bengal, which Is loud speaker only
slightly less loud than lion, could roar
or snarl indefinitely without attracting
the auditory attention of passersby.
Possibly that is the reason so many
visitors to Manhattan are captured by
blind tigers.