Beyond suppression: Self-generation enhances perceived loudness and cortical responses to faint sounds

Perceptual and neural attenuation for self-generated (SG) sounds at clearly audible intensities is well established, yet recent work suggests a reversal at near-threshold levels, with SG sounds perceived as louder. Here we tested whether this near-threshold perceptual enhancement is mirrored by enhanced early auditory cortical responses. Healthy adults (N = 47) performed an auditory intensity discrimination task, in which we manipulated sound source (self- versus externally generated) and intensity (near-threshold versus supra-threshold). We quantified perceptual bias using the point of subjective equality (PSE) and assessed early sensory processing with auditory ERPs. We observed a significant interaction between sound source and intensity both on PSE and N1 amplitudes. Self-generation enhanced the perceived loudness of near-threshold sounds, whereas the expected perceptual attenuation for supra-threshold sounds was not significant. Neurally, self-generated near-threshold tones evoked larger (more negative) N1 amplitudes than externally generated tones. At suprathreshold intensities, only P2 showed reliable attenuation for self-generated sounds, with no significant effects on N1. Moreover, self-generation abolished the typical N1 scaling with intensity observed during passive listening: while during passive listening supra-threshold sounds exhibited greater N1 amplitude than near-threshold sounds, this effect disappeared when the sounds were self-generated. Together, these findings indicate that self-generation does not impose uniform sensory cancellation, but instead dynamically reshapes early auditory gain as a function of stimulus intensity. This pattern is consistent with a precision-weighting account in which action-based predictions up-weight weak sensory evidence while down-weighting reliable input, potentially in interaction with arousal/orienting mechanisms that modulate gain as stimulus salience increases.