The highest string on a guitar has a much higher pitch than the lowest string. That's because the high string causes the particles in the medium to vibrate much faster. The low string has slower vibrations. If you put your hand on the body of the guitar while you pluck a string you can feel those vibrations. How many times the particles vibrate in one second is called the frequency.
Watch this animation to learn more about the relationship between a sound wave's pitch and a sound wave's frequency.
Stop the animation any time, watch it again, or read the transcript.
| Keyboard Shortcut | Action |
|---|---|
| Space | Pause/Play video playback |
| Enter | Pause/Play video playback |
| m | Mute/Unmute video volume |
| Up and Down arrows | Increase and decrease volume by 10% |
| Right and Left arrows | Seek forward or backward by 5 seconds |
| 0-9 | Fast seek to x% of the video. |
| f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
| c | Press c to toggle captions on or off |
A sound like this (high pitch) and a sound like this (low pitch) are different. But how? Both waves have the same amount of energy--each particle is getting pushed the same distance, therefore they are the same volume--but the rate at which they vibrate is different.
The rate of vibrations per second is called frequency. If the vibrations are more frequent, the higher the pitch. If the vibrations are less frequent, the lower the pitch.
To change the pitch of a sound, you have to change how many times the medium vibrates per second. Take a guitar string, for instance. As you tighten the string, the number of vibrations the string produces per second (frequency) increases and so does the pitch. Lower that string tension, and the vibrations per second (frequency) decrease and so does the pitch.
So hit that dance floor again, and this time, feel the vibrations--per second.
In the space below write one sentence that describes how a high-pitched sound is different from a low-pitched sound. Then write another sentence that describes the relationship between pitch and frequency.