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BELL SYSTEM TECHNICAL JOURNAL 



curves for business noise, the curves for residence noise are very sym- 

 metrical, showing similar distributions above and below the average 

 values. 



As shown on Figs. 6 and 7, the median residence room noise would 

 produce a reading of 7 db on the meter, and a masking of 12 db on the 

 high-frequency warbler tone, 20 db on the middle-frequency tone, and 

 13 db on the low-frequency tone. The average was about the same as 

 the median. 



The average of the room noises measured in single-family houses was 

 practically the same as the average of the noises measured in apart- 

 ments. 



Averages of the residence room noise measurements obtained in 

 towns of various sizes are shown in the following table: 



It will be observed from this table that the residence noises measured 

 in large cities were no greater than those measured in smaller towns. 

 A study of the data showed that 27 of the i?) measurements made in 

 Class A towns were made in residences which would be classed as apart- 

 ment houses. It is possible that the noise usually associated with big 

 cities is confined chiefly to non-residential locations, and that apart- 

 ments on side streets are no noisier than residences in smaller towns. 

 It should be recalled, however, that the number of measurements in 

 each class of town was very small. In any case the data tend to show 

 that the difference between residence noise in the large city and that in 

 the smaller town probably is not extremely large. The measurements 

 for Class A cities were made chiefly in Manhattan and Brooklyn with 

 a small number in Newark. 



It was found, in a manner similar to that discussed above for business 

 noise, that the average residence room noise was quite complex in fre- 

 quency makeup, and apparently did not differ materially from the aver- 

 age business noise in the relative amplitudes of low and high frequen- 

 cies. 



Comparison of Room Noise in Winter and Summer. — Forty locations 

 were visited both in summer and in winter and the data compared. It 

 was found that both business and residence noises were somewhat 



