Headphone lateralization is one-dimensional whereas free-field localization is three-dimensional for sound images

Evidence

In this case, the sound image is usually located within the head. In such a situation, the task of the subject is to describe the perceived lateral displacement of the sound. This displacement can be projected onto a straight line, which connects the entrances to both ear canals. In contrast to localization, a three-dimensional phenomenon, lateralization is described along only one dimension. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1708

Categorization

• DEFINE: Makes the technical distinction between ‘lateralization’ (one-dimensional, inside the head) and ‘localization’ (three-dimensional spatial) explicit.