3-D-Printed Device Helps Computers Solve Cocktail-Party Problem Artificial-intelligence researchers have long struggled to make computers perform a task that is simple for humans: picking out one person speech when multiple people nearby are talking simultaneously.

It is called the �cocktail-party problem�. Typical approaches to solving it have either involved systems with multiple microphones, which distinguish speakers based on their position in a room, or complex artificial-intelligence algorithms that try to separate different voices on a recording.

But the latest invention, described in this week Proceedings of the National Academy of Sciences, is a simple 3D-printed device that can pinpoint the origin of a sound without the need for any sophisticated electronics.

The device is a thick plastic disk, about as wide as a pizza. Openings around the edge channel sound through 36 passages towards a microphone in the middle. Each passage modifies the sound in a subtly different way as it travels towards the centre�roughly as if an equalizer with different settings were affecting the sound in each slice, explains senior author Steven Cummer, an electrical engineer at Duke University in Durham, North Carolina.