These vibrations can then be used to reconstruct sound with purity and fidelity, enabling the capture of isolated audio with no interference, and no microphone.

Beyond the system’s technical prowess, it opens up a world of potential possibilities.

To be able to “see” sound, the scientists have developed a camera system capable of capturing the slightest vibration with high precision. Composed of two cameras and a laser, the imaging device allows them to visualise what’s usually invisible to the naked eye.

The captured sound can then be reproduced in a clear, pure way, with no interference or ambient noise.

To demonstrate their discovery, the researchers managed to capture isolated audio of separate guitars playing together, and individual speakers playing different music at the same time. They analysed the vibrations of a tuning fork, as well as those made by potato-chip packets placed near a speaker.

The dual-camera setup, which uses two ordinary cameras, produces high-quality recordings and is capable of capturing vibrations from objects in motion. The system works by analysing speckle patterns in the captured images. This is the way light behaves in space after being reflected from a rough surface.

An algorithm then calculates the difference between these patterns and converts them into vibrations to reconstruct the corresponding sound

This optical microphone effectively “sees” otherwise invisible vibrations and opens up new perspectives in potential applications. It could prove revolutionary for sound engineers, for example, who could have a band or orchestra play together while monitoring each instrument individually.

Another possible application could be the monitoring of industrial machinery, so that a suspicious noise – otherwise imperceptible to the ear – could be investigated to preempt maintenance.