Researchers from the University of Southampton and the National Oceanography Centre (NOC) will ‘listen’ to a UK city for the first time at scale through its network of optical fibre cables using a ground-breaking new technology.
The researchers will be using an emerging technology called Distributed Acoustic Sensing (DAS) to capture sounds and vibrations throughout London and Southampton’s underground optical fibre networks.
It’s part of a new project called SOUNDSCALE to explore the opportunities and risks this technology presents before it becomes more established and to determine priorities for future research.
The team are particularly interested in how DAS could be used in marine cities as an ‘early warning signal’ for flash floods, storm surges and other environmental hazards.
What is DAS?
DAS turns the optical fibres that support our telecommunications networks into delicate sensor arrays that detect vibrations, like sound or movements.
As light travels along a fibre optic cable, a small amount scatters back due to natural imperfections in the glass, called Rayleigh backscatter. A vibration or disturbance anywhere along the length of the cable, such as from an earthquake, vehicle or even a footstep, influences this backscattered light.
DAS uses a highly sensitive instrument connected to one end of the fibre to detect these changes in the fibre’s ambient environment. These are then processed by advanced algorithms to interpret the nature and location of the vibration.
“DAS is an emerging technology that essentially turns the vast network of existing optical fibres within telecommunication and energy cables into an array of passive listening devices that are several kilometres long,” says Dr Rafael Mestre , a lecturer in emerging technologies at the University of Southampton, who is leading the SOUNDSCALE project.
Prof Mohammad Belal, a co-investigator on the project from the NOC, has been working on the development and use of distributed optical fibre sensors (DOFS), of which DAS is one example. He says: “The technology has come a long way from its initial use in the oil and gas sector to its more recent research in physical oceanography, seismic (marine and terrestrial) and infrastructure health monitoring.
“DAS can provide real-time insights into changing conditions that may signal impending environmental hazards such as flash floods, storm surges, or rising sea levels by continuously monitoring vibrations and disturbances in urban coastal environments.
“The technology could enhance flood warning systems by detecting underground water movements or shifting structural stresses, offering a new layer of data to complement traditional monitoring methods. This capability allows for earlier detection of unusual hydrodynamic activity, helping authorities to prepare and respond more effectively.”
Sound of a city
The research team consists of experts in physical sciences, engineering, computer science, political science, geography and arts and humanities.
London and Southampton have extensive optical fibre networks connected through the National Dark Fibre Facility (NDFF), enabling researchers to measure the ‘sound of a UK city’ for the first time at such a scale.
The team will be doing this in anticipation of the risks this technology might bring about.
“This technology poses potential risks to our privacy and security, opening up new opportunities for surveillance,” says co-investigator Dr Alexandra Anikina , a researcher in the Department of Art and Media Technology and Co-Director of Critical Infrastructures and Image Politics research group.
“DAS might change how we interact in shared spaces, and it’s important to work closely with local communities, not only through science and critical theory but also through the arts, to understand these changes.”
Engaging citizens
The team is planning to engage with citizens from both cities, through artistic exhibitions, policy workshops, and citizen panels that will help to steer the direction of further DAS research.
Prof Matt Ryan , co-investigator of the project and expert in public policy and democratic innovations from the University of Southampton says: “Too often new technologies change our lives before the public and policymakers have had a chance to engage with them in a meaningful way and consider what guard rails might be needed.
“With DAS we want to integrate citizens directly in its development and implementation so they can prioritise and anticipate issues before it is too late to change direction.”
The team are working with the National Centre for Social Research (NatCen), who hold extensive expertise in using deliberative methods to engage with citizens in complex policy topics.
“This approach ensures the technological deployment is sustainable, inclusive and beneficial to all segments of society, enabling truly ‘smart’ cities,” says Dr Ceri Davies, Director of the Centre for Deliberation at NatCen, and a co-investigator of the project.
Further research
Through this process, the SOUNDSCALE team will create new research projects involving experts from different fields to tackle issues like disentangling urban background noise from various dynamic events; exploring the link between noise pollution and public health; developing ethical frameworks for DAS deployment; examining how DAS can shape urban and coastal spaces, social inequalities and surveillance.
The project team also includes health geographer Prof Dianna Smith , and Dr Hannah Dalgleish, a policy expert and Knowledge Exchange Fellow.
It has been funded by UK Research and Innovation’s flagship cross-research council scheme. The scheme supports new and creative ideas and interdisciplinary research not usually funded.
