There are many misconceptions about how developed a tortoise’s senses are. Tortoises aren’t the fastest-reacting animals, so it’s normal to wonder if they can hear you.
Tortoises can hear low frequencies well. They can detect sounds between 10 and 182 Hz, whereas humans can hear sounds between 20 and 20,000 Hz.
They rely on vibrations to understand external stimuli, so sounds in higher frequencies go undetected.
Because tortoise hearing differs from ours, you should change how you interact with them. You may be surprised by how a tortoise reacts once you use a tone of voice suited to its sense of hearing.
Do Tortoises Have Ears?
Tortoises have ears, although many people think they don’t because their ears aren’t visible. However, that’s because their auditory system is internal.
Many animals are naturally deaf, but tortoises aren’t one of them. Complete deafness is rare in animal species. Only certain cephalopods, like squids and octopuses, are entirely deaf.
Tortoises need to be able to hear predators approaching. They have their shell, which is a great defense mechanism, but it would be a useless feature if they can’t even hear their enemy coming until it’s too late. They can’t always see what’s around them, so they rely on their hearing to know if they’re safe.
There are many theories as to why tortoises don’t have visible ears, but the most accepted one is because their bodies are low to the ground.
The pinna, the fleshy parts of our ears that stick out of our heads, help us hear by channeling sound waves into our ears. Tortoises don’t have this body part because they benefit more from feeling vibrations throughout their entire body to amplify sound, not sound waves.
So, they have nothing external directing noises into their internal ear system.
Where Are Tortoise Ears Located?
Tortoises’ ears are located behind the eyes and above the jaw.
You may notice it as a circular indent on the sides of the tortoise’s face. Many people think there’s nothing under those indents because they resemble the hollow part of our cheeks underneath our cheekbones. However, the indents are sensitive parts of the tortoise’s face and should be left alone.
When caressing a tortoise, you need to avoid touching its ears. Tortoises love neck rubs, but their ears are sensitive. They have protective ear flaps separating their inner ear from the outside, but you should still avoid touching them.
If you can’t see the indents on the sides of your tortoise’s face, it doesn’t mean that your tortoise is deaf. Some tortoise species have more prominent indents than others.
Larger tortoise species tend to have visible indents since their heads—and therefore their auditory system—is bigger. As your tortoise grows, the ear flaps should become more noticeable.
How Does a Tortoise Hear?
Tortoises can hear due to a simple yet effective auditory system.
There are three main parts to a tortoise’s auditory system:
- Middle ear
- Inner ear
The tympanum is a thick membrane that’s about 0.25 millimeters thick. It’s the only visible part of a tortoise’s ear because it covers the ear cavity under the tortoise’s eyes.
It doesn’t block sounds out of the tortoise’s ears. It helps tortoises perceive vibrations easier and protects the inner part of the ear cavity.
The middle ear is the largest part of a tortoise’s auditory system. It’s directly behind the tympanum and is the first part of the tortoise’s auditory system to perceive vibrations.
The vibrations perceived by the middle ear are sent to the inner ear. The inner is a network of complex membranes, tubes, tissue, and sinuses.
It’s next to the tortoise’s brain and is separated from the middle ear by the pericapsular sinus. This is an extension of the perilymphatic system.
The perilymphatic system is one of two cochlear systems that contain inner ear fluid.
How Well Can Tortoises Hear?
According to the German Society for Herpetology and Herpetoculture, tortoises have a limited hearing range that can only perceive 10-182 Hz. Humans can hear between 20-20,000Hz.
Tortoises can hear infrasound on the lower end of the spectrum, meaning they can hear low-frequency sounds that humans can’t detect.
Tortoises are designed to hear sounds at such low frequencies due to how they move around. Tortoise bodies are always close to the ground, so they benefit greatly from detecting ground vibrations instead of sound waves in the air.
Experts believe that tortoises evolved to hear sounds at such low frequencies so that they can hear predators walking toward them from afar. They’re small creatures, so they can’t see things from their point of view.
Tortoises have excellent hearing and know when to hide to protect themselves from danger. It isn’t fully known just how far they can hear, but experts theorize that the stronger the vibration produced by the sound is, the farther the tortoise can perceive it.
Can Tortoises Be Deaf?
Tortoises aren’t naturally deaf, but it might be possible for them to become deaf if their auditory system is injured somehow. Some animals can repair their auditory system if it becomes damaged, but it isn’t known if tortoises are such animals.
It was previously thought that tortoises were deaf for many years, even by scientists. Researchers would test tortoises by playing different sounds, only to find that they barely reacted.
However, the sounds they would play often exceeded their ability to detect them. Now that we understand which frequencies they can detect, we know that tortoises aren’t deaf.
If the tortoise’s auditory system is damaged somehow, the tortoise can become deaf. While hearing loss can’t be restored in humans without using a technological device, other creatures in the animal kingdom have been shown to have amazing regenerative abilities.
These allow them to repair their auditory system and keep their hearing.
Are Tortoises Sensitive to Noise?
Tortoises are sensitive to noises on the lower end of the frequency scale. Tortoises have difficulty detecting frequencies above 182Hz, so they aren’t sensitive to high-pitch noises like dogs and cats are.
Tortoises are especially reactive to sounds between the 117-170Hz range. Humans don’t typically produce sounds like that on their own, so you don’t have to worry about scaring your tortoise by producing a loud sound. What you should be careful of is letting other animals near the tortoise.
Cats produce purrs with frequencies between 25-150Hz, while dogs can growl with a frequency of 80-300Hz. Your tortoise might hear these sounds and think it’s a predator.
If you notice that your tortoise hides in its shell or burrow when your other pet makes a sound, you need to soundproof the room your tortoise is staying in.
Can Tortoises Hear Humans?
Tortoises can hear human noises, especially as we walk around the house.
Even if they can’t hear what we say when we speak to them in a high-pitched voice, they can still feel the vibrations caused by our footsteps if they’re close enough to the floor.
Studies show that human clapping is the sound tortoises react to the most, second only to male voices. This means you should be extra careful when having guests over if you ever host a party.
The tortoise will hear any clapping, and all that noise could stress it out.
Can Tortoises Hear Music?
Due to their low-frequency sounds, tortoises like piano, organ, bassoon, and bass guitar music. They react favorably to opera music, especially when the singer has a bass-baritone range.
Whether tortoises enjoy listening to music is debatable, as there’s no evidence that they enjoy it, but there is no evidence to the contrary.
The only way to know if your tortoise likes it is by observing its behavior when you play music. If it moves toward the source, it’s at least curious about it and isn’t scared.
You should change the song or lower the volume if it hides or seems stressed. Never place speakers near your tortoise, especially if the song has a lot of bass sounds, as tortoises are sensitive to vibrations.