The long-eared owl has relatively large ear slits placed asymmetrically on the sides of its head, as in a majority of owls, with the left ear higher and right lower in order to allow them to absorb sound both from above and below.
The ear slit very nearly occupy the full height of the skull, being are about 38 mm (1.5 in), long and covered in movable skin flaps.
The right ear is about 13% larger based on freshly dead owls.
Due to its ear structure, the hearing of a long-eared owl is around ten times better at hearing high and medium pitches than humans.
Barn owls and boreal owl (Aegolius funereus) have (via convergent evolution) roughly similar ear structures, with the relative size of the ear structure and facial disc in owls generally indicative of the level of importance of acute hearing to their life history.
Owls with relatively smaller ear slits and shallower or vestigial facial discs tend to skew towards more crepuscular or partially diurnal behaviors, whereas owls such as long-eared owls are more or less entirely nocturnal.
It is well known that a majority of owls can hunt in darkness due to their extraordinary hearing, which allows them to pinpoint locations of prey, but they can also utilize their hearing to track intraspecific calls and activities and avoid predation risks.

The vocalizations of this species are highly variable.
Amongst owls of all ages, long-eared owls in Michigan were recorded to have made 23 different vocalizations.
Karel Voous considered them to likely be the most diverse vocalists of all owl species in the Northern hemisphere.
The song of the male long-eared owl is a deep whoop, which is repeated at intervals of several seconds.
It starts with some hoots at slightly lower pitch before reaching full volume and quality.
On calm nights, this song may carry over up to 1 to 2 km (0.62 to 1.24 mi) away (at least to human auditory perception).
The song of the male is around 400 hertz.
In North America, some observers have considered the male's song as analogous to the deep cooing of band-tailed pigeons (Patagioenas fasciata).
Females gives a weaker, less clear and much higher pitched song with a nasal quality.
In nearly all owl species, the females, despite being typically the larger sex, have smaller syrinx than the males and so tend to have less powerful voices.
The call of the female is at times compared to a weak tin whistle and is only audible at close range, being about 4-5 halftones higher than the song of the male.
Females usually call only in duet with male during courtship, but also when the nest is selected and around the beginning of incubation (probably in conjunction with food-begging).
In fact, close study has revealed that female calling may occur as frequently as every 2–8 seconds at times of night between nest selection and egg laying.
Both sexes utter a cat-like, somewhat hoarse jaiow notes or high yip-yip notes, the latter reminiscent of a call made by barn owls.
When disturbed near the nest holding young, both parents may utter a series of tinny tones, watt-watt-watt-watt.
During the period of courtship the male flies around and flaps its wing around, producing a clapping sound.
During the display flight, the male may make as many as 20 claps.
As with many owls, all ages may produce hissing sounds and bill snapping when they feel threatened, especially in the context of nesting.
Fledging young call all with high-pitched, drawn-out notes, variously transcribed as feek, peeyee and pzeei, and are often likened to the noise of a gate swinging on a rusty hinge.
The long-eared owl has relatively large ear slits placed asymmetrically on the sides of its head, as in a majority of owls, with the left ear higher and right lower in order to allow them to absorb sound both from above and below. The ear slit very nearly occupy the full height of the skull, being are about 38 mm (1.5 in), long and covered in movable skin flaps. The right ear is about 13% larger based on freshly dead owls. Due to its ear structure, the hearing of a long-eared owl is around ten times better at hearing high and medium pitches than humans. Barn owls and boreal owl (Aegolius funereus) have (via convergent evolution) roughly similar ear structures, with the relative size of the ear structure and facial disc in owls generally indicative of the level of importance of acute hearing to their life history. Owls with relatively smaller ear slits and shallower or vestigial facial discs tend to skew towards more crepuscular or partially diurnal behaviors, whereas owls such as long-eared owls are more or less entirely nocturnal. It is well known that a majority of owls can hunt in darkness due to their extraordinary hearing, which allows them to pinpoint locations of prey, but they can also utilize their hearing to track intraspecific calls and activities and avoid predation risks.
The vocalizations of this species are highly variable. Amongst owls of all ages, long-eared owls in Michigan were recorded to have made 23 different vocalizations. Karel Voous considered them to likely be the most diverse vocalists of all owl species in the Northern hemisphere. The song of the male long-eared owl is a deep whoop, which is repeated at intervals of several seconds. It starts with some hoots at slightly lower pitch before reaching full volume and quality. On calm nights, this song may carry over up to 1 to 2 km (0.62 to 1.24 mi) away (at least to human auditory perception). The song of the male is around 400 hertz. In North America, some observers have considered the male's song as analogous to the deep cooing of band-tailed pigeons (Patagioenas fasciata). Females gives a weaker, less clear and much higher pitched song with a nasal quality. In nearly all owl species, the females, despite being typically the larger sex, have smaller syrinx than the males and so tend to have less powerful voices. The call of the female is at times compared to a weak tin whistle and is only audible at close range, being about 4-5 halftones higher than the song of the male. Females usually call only in duet with male during courtship, but also when the nest is selected and around the beginning of incubation (probably in conjunction with food-begging). In fact, close study has revealed that female calling may occur as frequently as every 2–8 seconds at times of night between nest selection and egg laying. Both sexes utter a cat-like, somewhat hoarse jaiow notes or high yip-yip notes, the latter reminiscent of a call made by barn owls. When disturbed near the nest holding young, both parents may utter a series of tinny tones, watt-watt-watt-watt. During the period of courtship the male flies around and flaps its wing around, producing a clapping sound. During the display flight, the male may make as many as 20 claps. As with many owls, all ages may produce hissing sounds and bill snapping when they feel threatened, especially in the context of nesting. Fledging young call all with high-pitched, drawn-out notes, variously transcribed as feek, peeyee and pzeei, and are often likened to the noise of a gate swinging on a rusty hinge.
Long-eared owl