Neural response attenuation for shorter inter-onset intervals between sounds in a natural soundscape

Abstract

Sensory attenuation of auditory evoked potentials (AEPs), particularly N1 and P2 components, has been widely demonstrated in response to simple, repetitive stimuli sequences of isolated synthetic sounds. It remains unclear, however, whether these effects generalize to complex soundscapes where temporal and acoustic features vary more broadly and dynamically. In this study, we investigated whether the inter-onset interval (IOI), the time between successive sound events, modulates AEP amplitudes in a complex auditory scene. We derived acoustic onsets from a naturalistic soundscape and applied temporal response function (TRF) analysis to EEG data recorded from normal hearing listeners. Our results showed that shorter IOIs are associated with attenuated N1 and P2 amplitudes, replicating classical adaptation effects in a naturalistic soundscape. These effects remained stable when controlling for other acoustic features such as intensity and envelope sharpness and across different TRF model specifications. Integrating IOI information into predictive modelling revealed that neural dynamics were captured more effectively than simpler onset models when training data were matched. These findings highlight the brains sensitivity to temporal structure even in highly variable auditory environments, and show that classical lab findings generalize to naturalistic soundscapes. Our results underscore the need to include temporal features alongside acoustic ones in models of real-world auditory processing. HighlightsO_LINeural responses (N1, P2) to sound events are attenuated when inter-onset intervals are short, replicating classic attenuation effects in a naturalistic soundscape. C_LIO_LIAutomatic onset detection from complex, ecologically valid soundscapes enables fine-grained analysis of temporal auditory dynamics. C_LIO_LIThese findings highlight that temporal sensitivity in auditory processing persists even in highly variable, real-world acoustic environments. C_LI