The measurement of noise, with special reference to engineering noise problems

The loudness of complex sounds.

“…The validity of the reference-tone method of expressing loudness rests on the assumption that all tones represented by points on the same contour are not only equal in loudness to the standard frequency, but also are equally loud when compared with one another. Kingsbury found experimentally that this assumption was true, and his results have recently been confirmed by Churcher, King and Davies (7).…”

“…In one approach, which is a variant of the method of supra-liminal sense distances, the relation between stimulus and sensation is determined from estimates of the relative -loudness of tones of different intensity (7,12,14,17,22). A sound of a given intensity is presented to the listener, who compares it with the same frequency at a different intensity.…”

“…Then, choosing arbitrarily certain intensity values as the limits of the scale (for example, the average minimum audible value as the lower limit and 100 decibels above the 800 cycle threshold as the upper limit) one can construct empirically an arithmetic scale of loudness on the basis of the data. This has been done by Ham and Parkinson (14) and by Churcher, King and Davies (7). The numbers on such loudness scarles are related to each other in such a way that a sound twice as loud or half as loud as another sound will have a number approximately twice or half as large.…”