Click-intensity discrimination with and without a background masking noise

A study of intensity discrimination employing click stimuli revealed three unusual effects. First, clicks are difficult to differentiate with respect to intensity. Second, the Weber function differs from those usually obtained with stimuli of longer duration. Third, click-intensity discrimination is, improved by the addition of a continuous background noise. Since click stimuli have virtually no energy variations, these results cannot be explained by stimulus-oriented theories of detection and discrimination.