Lasers use a light beam to cut away tooth decay before filling cavities, resulting in less vibration and pain than traditional drills, says Barry Jacobson, a pediatric dentist at Mount Sinai Medical Center in New York.

WSJ: To Cut Tooth Decay: A Laser vs. a Drill

When sound waves enter the tube, the vibration of the droplets will cause the sensor to detect changes optically as the beam is disturbed, supposedly resulting in near-perfect vocal reproduction.

ENGADGET: Inventor patents laser microphone