Sound, brain, and bias: Dissecting the Laurel-Yanny illusion with auditory and cognitive markers

This study aims to explore the acoustic, perceptual, and cognitive mechanisms underlying the Laurel-Yanny auditory illusion. A total of 60 volunteers aged between 18 and 28 years (M = 22.36 ± 2.17), all with normal hearing and a Montreal Cognitive Assessment score of ≥21, participated in the study. Participants' perceptions of the Laurel-Yanny auditory illusion were evaluated, and they were administered the Frequency Pattern Test, the Spectral-Temporally Modulated Ripple Test (SMRT), and the P300 test. A statistically significant difference was found in SMRT results between participants who perceived "Laurel" and those who perceived "Yanny," with the "Yanny" group having a better SMRT performance (p = 0.026). No significant differences were observed between the groups in the results of the other assessments (p > 0.05). Among participants who perceived "Laurel," a moderate negative correlation was found between SMRT results and P300 latency (r = -0.525, p < 0.01). These findings suggest that the differences in responses to the Laurel-Yanny auditory illusion may not solely be attributed to cognitive or attentional processes but may also involve differences in lower-level auditory processing mechanisms. The results indicate a potential interaction between auditory frequency resolution, spectral discrimination, and cognitive processing time.