Neural tracking of continuous acoustics: properties, speech‐specificity and open questions

Abstract

Human speech is a particularly relevant acoustic stimulus for our species, due to its role of information transmission during communication. Speech is inherently a dynamic signal, and a recent line of research focused on neural activity following the temporal structure of speech. We review findings that characterise neural dynamics in the processing of continuous acoustics and that allow us to compare these dynamics with temporal aspects in human speech. We highlight properties and constraints that both neural and speech dynamics have, suggesting that auditory neural systems are optimised to process human speech. We then discuss the speech‐specificity of neural dynamics and their potential mechanistic origins and summarise open questions in the field.

How the Listener’s Attention Dynamically Switches Between Different Speakers During a Natural Conversation

“…When the listener shifted attention, we observed intertwined fluctuations of INS at the switching time point; that is, INS between the listener and the to-beignored speaker was significantly suppressed, whereas INS between the listener and the to-be-attended speaker was significantly enhanced. Current oscillatory models of speech processing suggest that different neural oscillations decode distinct levels of speech information and that fast oscillations (gamma) are hierarchically phaselocked to slow oscillations (alpha, theta, or both; Ding & Simon, 2014;Giraud & Poeppel, 2012;Zoefel & Kösem, 2024). In other words, low-frequency oscillations impose periods of inhibition and excitation on high-frequency neural dynamics.…”