Simple loudness judgment tests were performed by a jury of 15 observers on the recorded noises of approximately 100 highway trucks. The loudness of the noises calculated by a modification of the equivalent tone method proposed by Beranek and co‐workers ranges from about 20 to 200 sones. Observers were instructed to rank the noises in six loudness classes and were allowed to listen to a sample of class 1 and class 6 after each 20 recordings. The calculated loudnesses were then divided into six classes with class limits set by a 40 percent loudness increase per class. Although the subjective tests were conducted with no elaborate controls, a correlation coefficient of 0.94 was found between the average judgment of the group and the calculated loudness class. The correlation coefficient between average judgment and total sound pressure level was 0.78, whereas the correlation coefficient between the average judgment and the level on the A‐network of the sound level meter was 0.83. Experimental techniques and the capabilities and limitations of the loudness‐calculation methods are discussed.

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