Many listening experiments employ so-called "pink" and "white" noise, including those to find the threshold of detection (TOD). However, little research exists that compares the impacts of these two noises on a task. This study is an investigation of the TODs at whole and third octave bands using pink and white noise. A modified up-down method was utilized to determine the TOD in white and pink noise at eight frequency levels using a dB boosted bell filter convolved with the original signal. Six graduate students in audio engineering participated. Subjects were presented with an unfiltered reference signal followed by a filtered or unfiltered signal and then were instructed to respond “same” or “different”. Correct answers decreased the filter boost while incorrect answers resulted in reversals that would increase the filter boost until the subject answered correctly. A trial would conclude when a total of ten reversals occurred. The filter boost levels of the last five reversals were collected to obtain an average threshold value. Results show no significant differences between white and pink noise TOD levels at all frequency intervals. Additionally, the JND between the original and the boosted signal was observed to be ±3 dB, consistent with existing literature. Therefore, it can be suggested that white or pink noise can be equivalently employed in listening tests such as TOD measurements without impact on perceptual performance.
