This chapter provides a wide comparative perspective on the behavioural and neural capacities for vocalization processing in general, and for cross-species voice processing in particular. Vocal communication usually takes place among conspecifics, but in certain cases heterospecific vocalizations can also help optimize behaviour. Vocal anatomy and the neurophysiological processes of voice production are highly conserved across vertebrates, and the perception of basic biological meanings from vocalizations is thus based on auditory cues that are not species-specific. This chapter suggests that these similarities, and also the general ability to learn about vocal sounds, provide a good basis to assume that specific cues in heterospecific vocalizations may be efficiently processed. The chapter reviews the anatomical, behavioural, and neuroscientific evidence suggesting that heterospecific vocalization processing may work efficiently across a wide range of taxa, and shares the neural substrates involved in the processing of conspecific communication sounds.