Face scanning The shape of a person's face has also come under biometric scrutiny. Devices can now analyze faces even if turned to the side by 35 degrees. A computer program breaks the images into a code and analyzes it with other faces at the rate of 10,000 faces per second. And identical twins, especially children, can pose a problem for face scanners. Recognition Systems' Hand Reader Hand recognition Hand scanning measures the length, width and height of a person's fingers and hand.
Systems can also measure the vein patterns of person's hand and wrist.
Unlike fingerprints, hand scanning carries no stigma of criminal activity. But hand geometry can change over time, making it less reliable in the long run than fingerprints. Voice recognition Voice recognition systems listen for various speech patterns to determine identity. A spoken password of a specific length grants access. Because voice recognition systems are fairly unreliable, they are often used in conjunction with other security measures, such as security cards.