Why Can You Hear a Mosquito's Wings but Not a Slowly Flapping Bird's?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why can you hear a mosquito's wings but not a slowly flapping bird's?

The Big Idea

You hear a mosquito's wings because they beat hundreds of times each second! That is fast enough to make a tone your ears can hear. A bird's wings flap far too slowly to make a tone.

Mosquito Wings

Step one: a mosquito's wings. A mosquito beats its tiny wings hundreds of times each second. Each beat pushes the air, and together they make a high whine near your ear.

Bird Wings

Step two: a bird's wings. A bird flaps only a few times each second. That is too slow to hear as a tone, so you just hear a soft whoosh, if anything.

Our Hearing Limit

Step three: our hearing limit. Our ears hear a tone when vibrations come faster than about 20 times each second. Slower than that is called infrasound.

A Closer Look

Let's take a closer look! The mosquito's wings blur because they beat so fast. The bird's wings flap slowly and gracefully. Fast beats blend into a high tone. Slow beats just push air in a soft whoosh.

Quick Facts

Quick facts! Sounds below about 20 vibrations a second are called infrasound. Elephants and whales use infrasound to talk across long distances. Bees buzz lower than mosquitoes because they beat their wings more slowly. A pure tone is just a steady, fast vibration.

Think Like a Scientist

Now, try this! Wave a ruler slowly through the air and listen. Then hold it on the edge of a desk and flick it so it buzzes. Why does one make a tone and the other not? Share what you discover with a grown-up.

Outro

Fast wings buzz, and slow wings whoosh. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!