Ever wondered how some people seem able to keep up with the conversation they’re having while also noticing what’s being said across the room? New research suggests this ability isn’t simply good hearing but that it may reflect the brain’s remarkable capacity to briefly process more than one conversation at once.
Scientists at Trinity College Dublin have discovered that, for a short period of around one to two seconds, the brain can begin following a new conversation before it has fully let go of the previous one. The findings, published in leading international journal PLOS Biology , challenge the long-held view that we can only focus on one speaker at a time.
The discovery may help explain why some people are particularly good at navigating busy social situations, whether that’s discreetly picking up useful information, keeping an ear on an important announcement, or deciding whether another conversation is worth joining without completely losing track of the one they’re already in.
The researchers measured participants’ brain activity using electroencephalography (EEG) while they listened to two people speaking at the same time against a background of crowd noise. Participants were asked to switch their attention between the speakers while the researchers tracked how their brains responded.
They found that the brain starts engaging with the new speaker before it has fully disengaged from the first, creating a brief overlap in which both conversations are represented simultaneously. And this is visible on the EEG via a unique neural signature that pops up as the process occurs.
Professor Giovanni Di Liberto , from Trinity’s School of Computer Science and Statistics, the Trinity College Institute of Neuroscience (TCIN) , and the ADAPT Research Ireland Centre for AI-Driven Digital Content Technology hosted by Trinity , is one of the senior authors of the research.
He said: “Our findings suggest that some people may naturally be better multitaskers than others, allowing them to better explore what’s happening around them without immediately losing focus on their current conversation. This could help explain why some people seem especially good at navigating busy social environments.”
“Because this brief ‘dual tracking’ ability seems to differ from person to person, it potentially gives some individuals an advantage in situations where rapidly shifting attention is valuable.”
What is the potential impact of this research?
The work also has important practical implications because understanding how the brain naturally switches between competing voices could help scientists develop better hearing technologies, including smarter hearing aids that support not only focusing on one speaker but also exploring the wider sound environment more naturally.
It could also improve understanding of why some people, including older adults and those with hearing difficulties, find busy places such as restaurants, workplaces and family gatherings particularly exhausting.
Ultimately, the work offers fresh insight into one of the brain’s most impressive everyday skills: helping us stay engaged in one conversation while remaining ready to respond when something more important catches our ear.
This work brought together scientists from Trinity, TCIN and ADAPT (Dr Sara Carta and supervisors Prof. Giovanni Di Liberto and Prof. Alejandro López Valdés), and the Eriksholm Research Centre (part of Oticon; co-supervisors Emina Aličković and Johannes Zaar). It was supported by funding from Research Ireland and the Demant foundation, and was organised via the Research Ireland Centre for Training in AI (CRT-AI).
PLOS Biology
Experimental study
Competing speech streams are simultaneously represented in the human cortex during attention switching
The authors have declared that no competing interests exist.