Vocal activity is almost entirely confined to the colder months from late fall through winter, with vocal activity in October through December mainly having territorial purposes and from January to February being primarily oriented towards courtship and mating purposes. Vocalizations in a Spanish study begin no sooner than 29 minutes after sunset and end no later than 55 minutes before sunrise. The territorial song, which can be heard at great distance, is a deep resonant "ooh-hu" with emphasis on the first syllable for the male, and a more high-pitched and slightly more drawn-out "uh-hu" for the female. It is not uncommon for a pair to perform an antiphonal duet. The widely used name in Germany as well as some other sections of Europe for this species is "uhu" due to its song. At 250–350 Hz, the Eurasian eagle-owls territorial song or call is deeper, farther-carrying and is often considering "more impressive" than the territorial songs of the great horned owl or even that of the slightly larger Blakiston's fish owl, although the horned owl’s call averages slightly longer in duration. Other calls include a rather faint, laughter-like "OO-OO-oo" and a harsh "kveck-kveck". Intruding eagle-owls and other potential dangers may be met with a "terrifying", extremely loud "hooo". Raucous barks not unlike those of ural owls or long-eared owls have been recorded but are deeper and more powerful than those species’ barks. Annoyance at close quarters is expressed by bill-clicking and cat-like spitting, and a defensive posture involves lowering the head, ruffling the back feathers, fanning the tail and spreading the wings.