Ears has the potential to give a project “ears”.

Ears is an Arduino shield that can give a robot, toy or other project the ability to respond to sound.

It consists of two electret microphones that connect to an easily assembled printed circuit board.

The board contains two microphone preamplifiers with gain adjustments, a connector for a servo and a regulator for the servo. Level is indicated by left and right LEDs which can be mounted on the board or extended to be used as decorations for a toy.

The Ears board can be plugged into an UNO which it can optionally power, or it can be operated independently when using other controllers.

Free test and operating sketches are provided. They determine sound levels and, more importantly, the direction of sound by means of a quadrature-like algorithm which simulates two comparators with trigger set points and two flip-flops.