Sensory Perception of expected and unexpected tones

Self-generated tones are processed differently compared to externally generated sounds (Horváth, 2015). This could be observed in both behavioural and electrophysiological measurements. One explanation for this effect might be a modulation by expectations, i.e., expected tones are perceived as attenuated (Friston, 2005). This theory is mostly supported by electrophysiological studies, with reduced neural signals for self-generated tones (e.g., van Laarhoven et al., 2021), but on a behavioral level the evidence is less clear. In any case, the behavioral effect indicating that participants perceive reduced loudness of a tone for self- relative to externally generated tones seems to be quite small (Cao & Gross, 2015; Weiss et al., 2011). For expected vs. unexpected tones, no differences in the perceived loudness has been found (Dogge et al., 2019), which, however, could be explained by the small effect size. In the current experiment, we aim to investigate whether self-generated unexpected tones are perceived as louder than self-generated expected tones. To do this, we aim to increase the behavioral effect by using a more externally valid and complex task, and using a scale instead of a binary response to assess loudness perception.