A new microphone watches vibrations and turns them into sound

Researchers at the Beijing Institute of Technology have developed a novel, low-cost visual microphone that captures sound by detecting tiny vibrations on everyday objects using light rather than traditional acoustic methods. This system employs single-pixel imaging—a simpler and cheaper technique compared to previous optical microphones that required expensive high-speed cameras or lasers. By shining light on surfaces such as paper, leaves, or plastic cups and measuring changes in reflected light intensity caused by sound-induced vibrations, the device reconstructs speech and other audio through advanced algorithms. This approach works under natural lighting conditions and does not depend on specific reflective properties of the surfaces. The innovation offers significant advantages in affordability and versatility, potentially enabling integration into smartphones, drones, or surveillance tools. It can detect sound through barriers like glass, making it useful in scenarios where conventional microphones fail, such as search and rescue operations or remote monitoring. However, the technology also raises ethical concerns due to its potential for covert eavesdropping without physical microphones. The researchers emphasize their intent to advance sensing technology