Significant Incidental Factors in the Measurement of Auditory Sensitivity

A theoretico-historical review of the threshold concept.

“…Considerable experimental evidence is now available which supports the contention that psychophysical judgments, on which threshold measures (and, hence, sensitivity) are based, are affected by a wide range of manipulable conditions. Some of these relate to the physical stimulus, such as rate of onset (Goodfellow, 1946) in which higher thresholds were obtained with increased time delays; some relate to the physiological state of the observer such as sleeplessness, although Goodhill and Tyler (1947) found that 100 hours of experimental insomnia had no effect on hearing acuity. Among the psychological factors, Senders and Sowards (1952) have found that subjects yield proportions of judgments in accordance with their expectations based upon their knowledge of the experimental situation.…”