MEASUREMENT OF NOISE KAYE 163 



The question of noise tolerance seems, however, to be largely one 

 not only of sensitivity, whether chronic or temporary, but of the 

 " background " of noise that one is used to. If external sounds are 

 completely excluded, adventitious noises are the more trying. An 

 amusing illustration is provided in Mar^^ Kingsley's book on West 

 Africa (1897), where she complains that "The African is usually 

 great at dreams and has them very noisily ! " 



It is within the experience of us all that the ticking of a clock, the 

 scratching of a mouse, the creaking of floors or furniture, the chirping 

 of birds are aggravatingly apparent during the stillness of night 

 in the country : such noises would be submerged in the higher noise 

 level of a city dwelling. What is unconsciously desired is not so 

 much the complete exclusion of noise, but only that the background 

 shall be at an agreeably low level to which one is accustomed. 



To sum up, the searching investigations undertaken on behalf of 

 the New York commission would indicate that, while most indi- 

 viduals, particularly the hale and hearty, can accustom themselves to 

 living or working in a noisy environment, there can be little doubt 

 that, in general, noise has a harmful effect on the mind, even of those 

 who are to all appearances immune to it. The evil effects are empha- 

 sized in the case of mental workers, young children, nervous or 

 fatigued individuals, and invalids. 



Before passing on, it is interesting to recall that " noise-money " 

 was at one time a recognized payment at sea. We read in Chambers' 

 Journal for 1883 that: 



So disagreeable is this fog-signaling duty . . . that . . . the whole crew re- 

 ceive wliat they call noise-money . . . for the time the signal is actually in 

 operation. 



DEFINITIONS OF NOISE 



Before going further, we should, I think, do well to try to come to 

 some agreement as to what we mean by a noise. To begin with, 

 "• noise " has ominous etymological relationship with " nuisance " and 

 "noxious;" and so, by analogy with the famous definition of dirt, 

 there is perhaps some justification for referring to noise as " sound out 

 of place." Althorigh we should scarcely expect to find this definition 

 in the New Oxford Dictionary, we are nevertheless given an almost 

 embarrassing choice reflecting the wealth of shades of meaning which 

 the word has assumed. In the sense, however, with which we are at 

 present concerned, Ave find that noise is there defind as : 



A loud or harsh sound or din of any kind; the aggregate of loud sounds 

 arising in a busy cummunity. 



The latter use of the word is well established, for, as long ago as 

 1651, we find in Hobbes's Leviathan, i, ii, 5 : 

 Obscured and made weak ; as the voyce of man is in the uoyse of the day. 

 149571—33 12 



