Sascha Hornauer was walking swiftly through the narrow corridors at ICSI’s former office space when he was struck by a realization. Although he had his eyes open, he was not navigating the space with vision alone. Whether approaching a blind intersection or dodging cars while crossing the street, we intuitively use sound to sense our surroundings. Some animals, such as bats, have honed this art to an incredible degree. Could machines do the same?
A couple of years later, Hornauer walked through those same corridors with a robotic system capable of using echolocation to “see” using sound in a real-world setting. Hornauer and collaborators Stella Yu and Jesper Haahr Christensen used a neural network to train the robot to predict the 3D depth of a scene using only the echoes of clicks it sensed with a pair of microphone “ears.” The system, dubbed Batvision, produced grayscale images of the scene with good accuracy in real time, demonstrating how the approach could help machines navigate low-light conditions—such as a smoke-filled room—without relying on expensive sensing technology such as radar and ultrasound.
The team presented their results at ICRA 2020, a leading global robotics conference, inspiring other researchers to continue to build upon and refine the technology. For Hornauer, who came to ICSI from Germany through the IFI-DAAD program, the project sparked further ideas that he is now pursuing in a tenure-track position at École des Mines de Paris in France. Who knows what new ideas lay around the corner?
What made ICSI a good place to pursue these projects?
“Due to ICSI being a small institute with many groups working in diverse domains, this led to a strong interdisciplinary exposure of ideas. ICSI facilitates this with social events and space to meet and relax. After the first few months at ICSI I had several friends across the institute and we went on trips through California together. I just came back from another little vacation with some of them, now six years later. I think ICSI’s strength is on one hand, supporting researchers professionally through help with project proposals and good infrastructure, but also by creating a welcoming atmosphere and sense of community.”
Sascha Hornauer
Former Postdoctoral Research Scientist; now Assistant Professor at MINES ParisTech
This story was published in January 2026 as part of a retrospective series highlighting ICSI’s accomplishments and impacts over the years. To learn about our ongoing work, explore our Core Research Themes.