Animals with the Best Hearing: The ability to hear has been evolving in animals for a considerable time. In fact, this ability has evolved differently in vertebrate and invertebrate species.
Table of Contents
- Vertebrates’ Unique Hearing Abilities
- 1. Common vampire bat – Highly sensitive hearing at the lowest frequencies on land
- 2. Barn owl – Highly sensitive directional hearing
- 3. Wolf – Best long-distance hearing
- 4. Pigeon – Best hearing at low frequencies among birds
- 5. Gentoo penguin – Can hear underwater
- 6. Humpback whale – Best low-frequency hearing underwater.
- 7. Killer whale – Best high-frequency hearing underwater
- 8. African Elephant – Best hearing of low frequency sounds on land
- 9. Rat – Sensitive to high-frequency sounds
- 10. Rabbit – One of the largest hearing ranges in daytime herbivore animals
- 11. Catfish – Best low-frequency hearing among fish
- Invertebrates’ Unique Hearing Abilities
Some animals have no need for hearing – for example, most beetle species are essentially deaf. Other animals do need to hear; still, certain factors influence the type of ears they have and the sensitivity of their hearing:
- Body plan/anatomy of the animal.
- The environment in which this particular animal lives.
- The lifestyle of the animal.
Vertebrates’ Unique Hearing Abilities
Most vertebrate animals can hear to some degree:
- Fish have -sensitive hairs cilia that can help catch the sound. Some fish also use their bladders or stones called otoliths in their skulls to catch the sounds in the water. Several fish, like catfish, have developed inner ears that are not unlike ours.
- Frogs lack outer ears. Still, they have the tympanum – the membrane that covers the inner ear and helps transmit sound.
- Reptiles are better adapted to hearing vibrations that are spreading through the land. Like frogs, they have a tympanum, a middle ear that contains a “hearing bone” – stapes, as well as the inner ear and a Eustachian tube.
- birds‘ ears are complex – they have an outer ear, middle ear, and inner ear. They also have ossicles – small ear bones and a tympanum, and a cochlea with sensitive hair.
- Mammals have the most complex ear structure compared to other tetrapod vertebrates. They have inherited the stapes bone from reptiles. Two bones from the -reptilian jaw have transformed in the course of the evolution into other two new bones malleus and incus. These bones assist in transmitting the sound in the middle ear. Mammals are also known for a great diversity of outer ears. Some mammals have huge ears, for instance, bats or some fox species.
We can meet the best vertebrate hearers among the two groups with better-evolved ears – birds and mammals.
Each animal has a specific hearing range. The sounds they hear can be measured in frequencies. The human ear usually can hear in a considerably wide range – from 20 Hz to 20000 Hz.
The sounds below 20 Hz are called infrasonic, and the sounds with higher frequencies are called ultrasonic. Many animals and insects have adapted to hear either in a broader range or to hear particular types of sounds, either infrasonic or ultrasonic.
1. Common vampire bat – Highly sensitive hearing at the lowest frequencies on land
Common vampire bats are small animals with relatively small (for bats) upright ears and black or brown fur. These bats can be found in the tropics and subtropics, where they predominantly feed on the blood of birds and large mammals. The sensitivity of hearing in bats is almost legendary:
- Bats ears’ shape assists them in catching sounds.
- Bats produce high-pitched sounds that are used for echolocation.
- Bats hearing range is more comprehensive compared to humans: from 716 Hz to 113 kHz.
- This particular bat species is unique because they have extreme sensitivity to, particularly, low sounds.
- It was discovered that vampire bats can also detect breathing sounds and even remember them.
2. Barn owl – Highly sensitive directional hearing
A barn own is a medium-sized owl with brownish and white feathers and a wide, almost heart-shaped face disk. The ears of the owl have certain unique features:
- They are hidden behind the feathers. There is no outer ear.
- The ears are located asymmetrically, one higher and one lower.
- The face disk of the owl helps it catch sound waves.
- The hearing range of the owl is between 200 Hz and 12 Hz.
- Hearing of the owl does not decline with age.
3. Wolf – Best long-distance hearing
A wolf is an efficient predator, and its sense of hearing is crucial for finding prey. The structure of the animal’s ears is optimal for its needs:
- The ears are triangular in shape and can rotate to better capture sounds.
- Ultimately, wolves can hear up to 80kHz, sometimes.
- The usual hearing range of the grey wolf is between 25 kHz.
- The wolf can hear sounds from a considerable distance, from 10 to 16 km, if there are no obstacles.
- Due to their acute directional hearing, wolves have excellent long-distance communication.
- Wolves and dogs can hear very quiet -sounds between 5 and -15 db.
4. Pigeon – Best hearing at low frequencies among birds
A common pigeon is a well-known city bird. It is very good at navigation and used to be a messenger bird. As a rule, birds are most sensitive to sounds in the range between 1-4 kHz. Yet a common pigeon is unique:
- The upper limit for a pigeon is as high as 10kHz.
- Pigeons can hear very low sounds – as low as 0.05 Hz.
- Such low sounds can help pigeons with navigation, detection of water sources, and predict weather changes.
- Compared to humans, there is a 50 dB difference in detection of low frequency sounds between humans and pigeons.
- Pigeons can hear those infrasounds from a considerable distance.
5. Gentoo penguin – Can hear underwater
Penguins are birds that usually live close to the shore, as their primary food source is fish. They have relatively good hearing, comparative to other birds. They also have some hearing abilities that are unique for them:
- The hearing range of the penguin is between 100 Hz and 15, 000 Hz.
- The penguins are known to make sounds underwater.
- Penguins can close down their ears when they deep dive.
- It was established that penguins can detect sounds underwater as high as 120 db and evade overly loud sounds.
6. Humpback whale – Best low-frequency hearing underwater.
The humpback whale belongs to the group of baleen whales. These whales have a unique structure, baleen, that acts as a net or filter that helps them catch krill. They are enormous animals, and their skulls are especially big. Humpback whales are known for singing underwater, and their hearing is specially adapted for this type of communication:
- The outer ear is a small opening in the skull without outer structures.
- Their middle and inner ear structures are modified for better hearing underwater.
- Whales hear a sound as vibrations through the water of different length.
- A specialized tympanoperiotic complex detects sounds with a shorter wavelength.
- Sounds with longer wavelengths are transmitted through the whale’s skull due to bone conduction.
- The hearing range of the humpback whale is between 15 Hz and 3 kHz.
- The humpback whales can hear low-frequency sounds from large distances.
- It was recently discovered that even prehistoric relatives of humpback whales could hear extremely low frequencies.
7. Killer whale – Best high-frequency hearing underwater
A killer whale is an iconic sea mammal. It belongs to the toothed whales’ group and can actively hunt large prey-including bigger whales. Hearing is a crucial part of its life – both for hunting and communication:
- Killer whales and their relatives specialize in detecting ultrasounds at high frequencies.
- To better localize the sound, the middle ear bones of the whale are isolated from their skulls.
- Its standard hearing range is from 0, 5 to 42 kHz, according to the latest research.
- In some cases, killer whales can detect sounds at higher frequencies that reach 120 kHz, though their sensitivity to such high sounds is low.
- Killer whales also use echolocation for detecting prey and coordinating hunting strategy, and hearing plays a huge part in this process.
8. African Elephant – Best hearing of low frequency sounds on land
Elephants are considered the largest land animals. They also have the biggest ears among land animals.
- Elephants’ large ears help them detect low-frequency sounds from the environment.
- Elephants can hear sounds as low as 10-16 Hz.
- Elephants do not have a keen high-frequency hearing – while humans can hear sounds as high as 20, 000 Hz, elephants detect sounds no higher than 12, 000 Hz.
- Elephants regularly communicate with low-frequency sounds.
- Elephants can detect underground vibrations with their feet, and this information is processed together with information on sounds.
9. Rat – Sensitive to high-frequency sounds
A common rat is an animal that is usually active at night. Some rats can search for food during the daytime as well. Predominantly nocturnal life means that rats need a sensitive hearing. Their hearing range is shifted towards higher frequency sounds compared to humans:
- Their standard hearing range is between 250 Hz and 80kHz.
- Rats are the most sensitive to sounds between 8 and 38 kHz.
- In their “comfortable” range, rats can hear very quiet high sounds that humans would not hear completely.
- The middle and inner ear structures of rats mature after birth, which is useful for scientists interested in how ears develop in mammals.
- Rats are often used for hearing research, as their ears are similar to human ones.
10. Rabbit – One of the largest hearing ranges in daytime herbivore animals
Rabbits are prey animals. Therefore, they rely heavily on hearing to detect possible enemies:
- The rabbit ears can rotate 270 degrees.
- Each rabbit ear can rotate separately to precisely pinpoint the direction.
- The rabbit hearing range is between 360 Hz and 42, 000 Hz.
- Rabbit ears also serve as an outlet for excess heat.
- Rabbits can detect sounds from a distance that exceeds one mile.
11. Catfish – Best low-frequency hearing among fish
A catfish is a large predatory freshwater fish living predominantly near the bottom of rivers and lakes. These fish have quite developed senses, including hearing:
- Catfish have inner ears similar to ours.
- The inner ears of a catfish contain semicircular canals for balance and fluid-filled sacs for hearing.
- The sacs inside the fish inner ears contain sensitive cells and structures called otoliths.
- Catfish have specific differences from other fish ears: they have more sensitive cells and large otoliths.
- Catfish can hear sounds from 50 to 1000 Hz.
- Their hearing is geared towards lower sounds, and they hear best in the range of 100-200 Hz.
Invertebrates’ Unique Hearing Abilities
In invertebrates, namely in insects, organs that helped them hear have evolved approximately 19 times.
- These hearing organs have often evolved from so-called chordotonal organs – special structures that are basically bunches of sensory cells located on the insect skeleton’s outer parts or hidden between tissue fibers.
- Many insect hearing organs detect both vibrations and sounds that travel through the air because of their origin. Many insect ears have a tympanum – a membrane that vibrates in response to sounds, similar to vertebrates.
- Still, not all insects have this structure. Another feature of insect hearing is that not every insect has ears on their heads. More often than not, insects have ears on very different parts of their bodies.
Here are the examples of the most unique ears in the world of insects:
1. Greater Wax Moth – Best ultrasound hearing
The greater wax moth is a relative of butterflies. Unlike butterflies, whose larvae mainly feed on plants, the larvae of greater wax moth feed on bees‘ combs.
The adult moths are often eaten by bats, so they have evolved highly sensitive hearing:
- Moths have eardrums that are attached to their bodies, not their heads.
- The hearing range of this moth species was discovered to be between 50-300 kHz.
- Wax moth hears the best at 80kHz.
- The bats can produce calls as high as 212 kHz, and the moths have developed a sensitivity to similar sounds to avoid their main predators.
- The moth hearing sensitivity is so precise that they can differentiate between the bat call and the equally high-frequency mating call of their own species.
2. Bladder Grasshopper – Serial ears without a tympanicmembrane
A bladder grasshopper is a nocturnal insect found in South Africa. This grasshopper species is most famous for its loud call.
This grasshopper has several unique features that help it hear:
- This species can send acoustic signals at a distance that can reach 2 km.
- The grasshopper has 12 “ear” organs located on its abdomen.
- The ears’ complexity increases from lower to the upper abdomen.
- The lower five pairs of ears consist of simple sensory cells and are similar to chordotonal organs.
- The ear pairs located in the upper region are more complex and can contain approximately 2000 sensory cells.
- The hearing range of a bladder grasshopper is 1.4 to 4 kHz.
- These insects hear relatively loud sounds – from 60 to 98 db.
3. Katydid – Highly sensitive ears with an eardrum
Copiphora gorgonensis is a small katydid found in Colombia. This insect resembles a grasshopper yet is, in fact, a kind of cricket. It has one small horn on its head. Recently, this insect has gained the attention of scientists because of the unique features of its ears:
- This katydid’s ears are located on the legs, right below its knee-like joints.
- Katydid’s ears have dual eardrums.
- There is a unique fluid-filled bubble or vesicle inside the katydid ear.
- Due to this structure, the katydid ears work similar to mammalian ears: the vibration of the eardrum is transmitted through the liquid to sensory cells.
- The hearing range of a katydid is between 5,000 and 50,000 Hz.
4. Praying mantis – A unique group of insects that have only one ear.
There are multiple praying mantis species. These insects are predators. They usually mimic harmless objects, like twigs, and wait for their potential prey – smaller insects. Mantises are often food source for bats as well. Previously, it was thought that mantises are deaf. This theory was later proven wrong:
- A praying mantis has only one ear.
- This ear is hidden in the insect’s chest.
- Mantis ear has two eardrums facing each other located in a special groove.
- Mantis can hear between 30 and 60 kHz.
- Mantis uses its ear to detect bat calls as a predator evasion strategy.
5. Mosquito – Best long-distance hearing
Mosquitoes are insects that are both well known and much disliked as carriers of several diseases. These insects can produce high-pitched sounds that are used for communication and finding mates. Their hearing has some interesting characteristics:
- Mosquito ears have no tympanum.
- Mosquito ears consist of long antennae covered in sensitive cells that detect sounds.
- Male mosquitoes have more sensitive ears than female ones.
- These antennal ears can sense sound waves at a relatively wide range: 150-500 Hz.
- The mosquitoes can hear sounds from as far as 10 m.
There is a surprising diversity of hearing adaptations among animals. In conclusion, we can say – it is not important what kind of ears you have, or how sensitive they are. The most important thing is WHO you want to hear.
Penguins can hear underwater!