How does your ear sort out high notes from low notes?

1Two things to know first

Pitch is a speed — and your ear has a strip that shakes

You only need two ideas. Watch each one:

A high note wiggles fast

Sound is a wiggle in the air. A high note wiggles super fast. A low note wiggles slow. That speed is what we call its pitch.

A curled strip can shake

Coiled inside your ear is a tiny ribbon — a "listening strip." It can shake when sound reaches it. And here's the trick: different parts are built to shake at different speeds.

2Your turn — play a note

Make a slow wiggle or a fast wiggle

Slide from low to high. Watch how many wiggles fit into the same space, then hear the note if you like. We will test the listening strip after your prediction.

The sound wave — same loudness, different pitch

◀ slower wigglesfaster wiggles ▶

Pick a note: middle

3Now flatten a spot

What if a patch in the middle stops moving?

The first test flattens a narrow patch in the middle of the model strip. Then we send in two notes: one low and one high. Predict their signals before inspecting where each note lands.

Guess before you tap

With a narrow middle patch flattened, which result will these two test notes give?

4Compare the ideas

One big ear, or a row of little ears?

The separate signals fit a place-based strip better than one lump. These two drawings compare the ideas.

Idea 1

One big ear

The whole strip shakes the same for every note. Sound is just one mixed lump, loud or quiet.

Idea 2

A row of little ears

Each note shakes its own spot — fast notes one end, slow notes the other. A place for every pitch.

5So why build it this way?

A row of little ears is amazing — but it has a catch

A place for every pitch

Because each note has its own spot, you can tell two notes apart, follow a tune, and pick a friend's voice out of a noisy room. That sorting is what makes music and speech make sense.

The catch: damage to hair cells can reduce hearing in some pitch ranges more than others. Very loud sound can permanently damage these cells.

This diagram simplifies the ear

Real notes excite overlapping regions of the cochlea. Hair cells and nerve signals work together to represent a sound.

The catch: our on/off patches make place-based sorting easy to see; they do not reproduce every kind of hearing loss.

Your ear doesn't hear sound as one lump. A curled-up strip inside sorts every note onto its own spot — fast highs at one end, slow lows at the other, like keys on a piano — and nearby hair cells turn the motion into nerve signals.

Psst, grown-ups: the "listening strip" is the basilar membrane inside the spiral cochlea. It is mechanically tuned along its length (this is called tonotopy): stiff and narrow at the base, where it resonates to high frequencies, and floppy and wide at the apex, where low frequencies peak. An incoming sound sends a travelling wave down the membrane that deposits each frequency's energy at its own place, and the hair cells there turn that motion into nerve firing. That's why a localized injury — loud-noise or age-related damage, which hits the high-frequency base first — causes loss of a specific pitch range rather than a uniform drop in overall volume.