Discriminating external from self-produced sensory inputs is a major challenge for brains. In the auditory system, sound localization must account for movements of the head and ears, a computation likely to involve multimodal integration. Principal neurons (PNs) of the dorsal cochlear nucleus (DCN) are known to be spatially selective and to receive multimodal sensory information. We studied the responses of PNs to body rotation with or without sound stimulation, as well as to sound source rotation with stationary body. We demonstrated that PNs are sensitive to head direction, and, in the presence of sound, they differentiate between body and sound source movement. Thus, the output of the DCN provides the brain with enough information to disambiguate the movement of a sound source from an acoustically identical relative movement produced by motion of the animal.dorsal cochlear nucleus | multisensory integration | sound localization A significant amount of sensory information reaching the brain of a moving organism results from the movement itself. Organisms have to disentangle self-generated sensations from the rest of the sensory input to use external sensory information for guiding behavior. To perform this disentanglement, brains integrate information from different sensory modalities and use efference copies of motor commands (1-3). This difficult challenge has been studied in several sensory-motor systems. In the visual system, the organism has to discriminate between movement of the visual scene and movement of the eyes (4, 5). Similarly, in the auditory system, it is necessary to discriminate between an actual motion of a sound source and the relative motion caused by movement of the head or the body (6). Moreover, it has recently been demonstrated that spatial acuity is improved during self-motion in comparison with sound-source motion (7). Here we show that neurons of the dorsal cochlear nucleus (DCN), which are known to be spatially selective (8,9), are affected by vestibular stimulation. We demonstrate that by integrating these two sensory modalities, the output of the DCN already contains enough information to reliably discriminate between self and sound-source motions.The DCN is a dome-like formation located on the dorsal surface of the lower medulla. Its anatomy and physiology have been thoroughly studied both in vivo and in vitro (9, 10). The principal neurons (PNs) of the DCN, the fusiform and giant cells, receive auditory information directly from the auditory nerve (11), as well as indirectly from other neurons in the cochlear nucleus. The DCN has cerebellar-like circuitry (9). A large number of granule cells contribute to a parallel fiber-like system that forms a molecular layer and conveys multimodal sensory information to the molecular layer interneurons as well as the PNs and cartwheel cells (9,(12)(13)(14) (Fig. 1A). Interneurons within the molecular layer, including the cartwheel cells, form inhibitory local networks that terminate on the PNs.Sound localization in mammals is based on binau...