in the case of A is several times greater than in that of B. I conclude that A is much more sensitive than B to such influences, and that there is here presented, in passing from intensity I. to intensity II., the rise of conditions under which the influence of the louder sound on B is first distinctly felt—­that is, the appearance of a threshold—­and that the rate of change manifested might not hold for higher intensities.

Lastly, the rate at which the sounds of the series succeeded one another was varied, in order to determine the relation which the amount of influence exerted bore to the absolute value of the intervals which it affected.  Three rates were adopted, the whole series of sounds occupying respectively 2.50 secs., 2.20 secs, and 1.80 secs.  The results are summed in the following table: 

TABLE XXXII.

Rate:  2.5 secs.  Rate:  2.2 secs.  Rate:  1.8 secs.

Ratio of Interval B    B        A        B        A        B        A
to Interval A.    +  =  —  +  =  —  +  =  —  +  =  —  +  =  —  +  =  —

1.000 :  1.000 2 8 0 0 8 2 0 8 2 0 2 8 0 4 0 0 2 2 0.917 :  1.000 0 8 2 4 6 0 3 8 0 0 8 3 2 2 0 0 2 2 0.846 :  1.000 1 9 0 5 4 1 3 8 0 3 7 1 6 5 0 1 8 2 0.786 :  1.000 1 10 0 11 0 0 6 6 0 7 3 4 6 2 2 2 6 2 0.733 :  1.000 4 2 0 4 0 2 4 6 0 8 0 2 0.687 :  1.000 5 3 1 6 1 2 2 6 0 7 0 1

  Totals 4 35 2 20 18 3 21 35 3 20 21 20 20 25 2 18 18 11*

  Transcriber’s Note:  Original “1”.

These results are converted into percentages of the total number of judgments in the following table: 

TABLE XXXIII.

Rate of B A Success. + = — Errors. + = — Errors. 2.5 secs 10 85 5 15 49 44 7 51 2.2 " 36 59 5 41 33 34 33 67 1.8 " 43 53 4 47 38 38 24 62

In the case of interval A the direction of the curve of error changes in passing from Rate II. to Rate III.  In the case of interval B the increase is continuous.

This increase in the percentage of error is, further, distinctly in the direction of an accentuation of the overestimation of the interval B, as is shown in the percentage of cases in which this interval appeared greater than the rest of the series for each of the three rates.

If the three rates be combined in the one set of results, the difference in the effects produced on the interval following the louder sound and on that which precedes it becomes again apparent.  This is done in the table below.

TABLE XXXIV.