Hearing facts for kids

A diagram showing the parts of the human ear

Hearing is one of our five senses. It lets us detect vibrations in the air around us. These vibrations are what we call sounds. Most animals can hear, and it's super important for them to find food, avoid danger, and talk to each other.

For mammals, like humans, sound travels through three main parts of the ear to be heard. These parts are the outer ear, the middle ear, and the inner ear.

• Outer Ear: This is the part you can see, called the pinna. It also includes the ear canal that goes inside your head. Sound waves first enter your ear through the pinna and travel down the ear canal. At the end of the canal is your eardrum, which vibrates when sound hits it.
• Middle Ear: After the eardrum vibrates, the sound moves deeper into your ear. Three tiny bones, the hammer, anvil, and stirrup, help carry these vibrations. They are the smallest bones in your body!
• Inner Ear: Finally, the sound reaches a small, snail-shaped tube called the cochlea. Inside the cochlea, there's a fluid that moves tiny hairs. These hairs send signals to your brain, which then understands and interprets the sounds you hear.

Hearing in Water

Have you ever tried to hear underwater? It's much harder for humans! Our ears are made for hearing in the air. Sounds underwater are quieter and harder to figure out where they come from.

This is because sound travels differently in water compared to air. But many aquatic animals, like whales, seals, and fish, have special ears. Their ears are perfectly designed to hear sounds in water.

How Animals Hear

A cat can hear very high-pitched sounds, much higher than humans can.

Not all sounds can be heard by all animals. Each animal species has its own range of sounds it can hear. This includes how loud a sound is (its amplitude) and how high or low it is (its frequency).

Many animals use sound to talk to each other. For these animals, hearing is super important for their survival. It helps them find mates, warn others of danger, and locate food.

What Sounds Can Animals Hear?

Sounds that humans can hear are called audio or sonic sounds. Our hearing range is usually between 20 Hz (very low) and 20,000 Hz (very high).

• Ultrasonic Sounds: These are sounds with frequencies higher than what humans can hear. Some bats use ultrasound for echolocation. This means they send out high-pitched sounds and listen for the echoes to find objects in the dark. Dogs can also hear ultrasound, which is why 'silent' dog whistles work for them.
• Infrasonic Sounds: These are sounds with frequencies lower than what humans can hear. Snakes can sense infrasound through their jaws. Large animals like baleen whales, giraffes, dolphins, and elephants use infrasound to communicate over long distances. Some fish, like carp and herring, have a special connection between their ear and swim bladder that helps them hear better.

Hearing in Insects

It's not just animals with backbones that can hear! Some insects also have special hearing organs. For example, long-horned grasshoppers, lubber grasshoppers, and cicadas all use sound to communicate with each other.

Understanding Hearing Loss

A behind-the-ear hearing aid, a device that helps people with hearing loss.

Sometimes, people have trouble hearing. This is called hearing loss. There are different types of hearing loss, and they can affect people in different ways.

• Mild Hearing Loss: People with mild hearing loss might find it hard to follow conversations, especially when there's a lot of background noise. They can usually hear sounds that are between 25 and 40 dB HL (decibels of hearing level).
• Moderate Hearing Loss: If someone has moderate hearing loss, they often need a hearing aid to keep up with conversations. They can usually hear sounds between 40 and 70 dB HL.
• Severe Hearing Loss: People with severe hearing loss rely on powerful hearing aids. They often also use lip-reading to understand what people are saying. They can usually hear sounds between 70 and 95 dB HL.
• Profound Hearing Loss: This is when someone is very hard of hearing. They often rely on lip-reading and sign language to communicate. They can usually hear sounds from 95 dB HL or more.

Hearing aids are electronic devices that help people with hearing loss hear sounds better. They make sounds louder and clearer, which can really improve a person's ability to hear and communicate.

Images for kids

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  The middle ear uses three tiny bones, the malleus, the incus, and the stapes, to convey vibrations from the eardrum to the inner ear.

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  The inner ear is a small but very complex organ.

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  The lateral lemnisci (red) connects lower brainstem auditory nuclei to the inferior colliculus in the midbrain.

See also

In Spanish: Audición para niños