Auditory intensity discrimination with bursts of reproducible noise

Auditory-intensity discrimination was investigated using gated bursts of reproducible noise. Weber fractions were determined at a number of energy levels with stimuli that differed in intensity, duration, & bandwidth. Weber's law was approximated in all cases. In addition, discriminability was found to be somewhat dependent on burst duration & relatively independent of noise bandwidth; threshold signal-to-noise ratios improved when duration was increased from 10 to 100 msec, but not when bandwidth was increased from 500 to 5,000 Hz. The data were compared with the results of a 2nd experiment in which the stimuli were random--rather than pseudorandom--noises. Finally, the results of both experiments were compared with predictions about intensity discrimination derived from 2 theoretical models: (1) a Poisson-counting mechanism; & (2) an energy detector incorporating additive internal noise. HA