The so-called time-error (TE) was considered here as the functional dependency of the time-order error (TOE) upon the time interval of the two stimuli. In particular, the present study was undertaken to analize these relations in tone discrimination with the comparative rating scale method.
In other words, the intent was related to the examination of (1) the phenomenon of TOE in pitch and loudness discrimination, andat the same time, of (2) the temporal aspect which manifests itself in the application of Helson's adaptation-level theory.
Two series of experiments were designed for pitch and loudness judgment respectively with almost identical procedure and these data were compared each other.
In the pitch judgment experiment, 16
Ss judged five tones (V), varying from 976 to 1024cps., with a standard (S) of 1000cps., 60db. sensation-level, in nine categories. The time intervals between stimuli were 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, and 8.0 seconds. In addition, 4, 5, 6, 7, and 8 seconds intervals were used for 8
Ss with two time-orders (S
1V
2 and V
1S
2).
AL values calculated by Helson's formula were, for all intervals, below the standard stimulus in two time-orders, but showed no characteristic change with varying time-intervals.
On the other hand, in the loudness judgment, experiment, where 16
Ss judged five tones, varying from 57 to 63db. with a standard 60db. 1000cps., the error in S
1V
2 order gradually increased its negative value as interval became longer. This trend was significant at 5% level in Mann's trend analysis. The error in V
1S
2 order was not significant, but was similar to Köhler's result. These difference between two experimental results may be explained in part by the psychological function in the attributes of tone and physiological acoustical mechanisms.
It was suggested by both experiments that the width of judgment scales were narrower in V
1S
2 than S
1V
2. Perhaps, in S
1V
2 those scales would be organized according to the central tendency.
The experimental values agreed with theoretical values when perceiving increment, but not when perceiving decrement of the stimulus being judged. This fact had relation to negativity of TOE.
It was discussed that the so-called TE would correspond to the upward or downward shift of the scale values owing to changes of intervals of the stimuli.
From the point of view of the AL theory, this would be nothing other than the fact that the value of AL might change corresponding to the change of stimulus interval.
Certain time parameters should be introduced into the adaptation-level formulation to make further explanation of these facts.
At any rate, we can conclude that a systematic TE was shown in loudness but not in pitch by the application of AL-theory. This fact is analogous with results obtained with the usual method of TE experiment, e.g, Postman's.
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