Abstract: The speed of an object is measured using a device which includes a transmitter spaced a predetermined distance from a receiver. A first sound wave is propagated through air with a first velocity, typically zero velocity. A second sound wave is propagated through air, the air having a second velocity which approximately equals the air speed of the object. The difference in time between the two sound waves reaching the receiver is measured and used to calculate the air speed of the object, which is then displayed to the user. The device is readily mounted on a pair of glasses wherein the user can read the displayed air speed without involving the user's hands.