Popis: |
Watson and Nichols [J. Acoust. Soc. Amer. 39, 1247, 1966(a)] described an experiment in which 10 tonal signals and 10 instances of noise alone were distributed randomly over the course of 5‐min listening periods. Although listeners responded at low rates, distributions of response latencies were estimated for signals plus noise and for noise alone, and from these distributions values of the detectability index, d′, were calculated. We now find that listeners can be trained to respond very frequently in this task when they are allowed to use low‐confidence ratings for faint signal‐like events in the noise background. Relations between ratings and the probability that a response is correct, relations between confidence level and response latency, and also the slopes of rating ROC curves (plotted on normal‐normal coordinates) are all similar to those from experiments with defined observation intervals. |