Abstract: A method and apparatus to enhance or improve the sound localization properties of hearing aids determines the interaural level differences required for localizing sounds to a specific point of origin. These determined interaural level differences are then used in the adjusting and fitting of the hearing aids. A number of hearing tests at different frequencies with a sound source that apparently moves relative to the test subject are performed, and by adjusting the response of the hearing aid in the left ear relative to the right ear, for example by attenuating the left ear, the amount of attenuation or gain can be found that causes the test subject to perceive that the sound source is located at a specific point of origin. These determined interaural level differences are then used to design a new hearing aid or to modify the existing hearing aid.