Intro
Every year, around 25 engineering students from various universities in Denmark take part in the Audio Explorers-challenge. The prize? A trip to a major city – traditionally New York City, and this year, Toronto.
But these trips are about much more than inspiring the next generation of audio engineers.
Participants are part of the study
While exploring the city, the students become research participants in a study led by Eriksholm Scientist Josefine Munch Sørensen. They wear sensors that continuously capture their heart rate, carry devices that record characteristics of the sound environment, and use GPS to track where they are. In other words: they generate a rich picture of what happens to people as they move through the real world together.
New findings on heart-rate synchrony
And the data keeps on giving. Data collected during three previous Audio Explorer trips to New York – involving 72 students and more than 1,000 hours of multimodal recordings – have now led to remarkable findings about heart-rate synchrony.
The research, recently published in PNAS Nexus, shows that people’s heart rates reliably synchronize when they are in close physical proximity. The synchrony is stronger between people who already know each other and during situations involving shared attention and interaction. Perhaps most interestingly, the sound environment matters too: synchrony is stronger when listening conditions are relatively favourable and disappears in very noisy environments.
Read more about the research here: Heart rate synchrony as a marker of real-world social engagement | PNAS Nexus | Oxford Academic)
So what started as an innovative student challenge in the streets of New York has become new scientific knowledge about social engagement, sound environments and what it means to be connected to the people around us.
In August 2026, a new group of Audio Explorers has been out collecting data in Toronto, Canada.
Who knows what discoveries those data will lead to?
A big thank you to all the curious and adventurous students who make these real-world research experiments possible – and to everyone at Demant and DTU who helps turn an exciting trip into meaningful science.
