A siren makes a strange, pulsing sound because it’s sending out many different sound waves at once. When the siren is moving toward you, the sound gets louder and higher, like when a car zooms past you on the road. And when it moves away, the sound gets softer and lower. This is called the Doppler effect, and that’s why sirens make such an interesting noise!
Examples
- You hear a police car’s siren change pitch as it passes by.
- An ambulance siren seems to go from high to low as it drives away.
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See also
- What Causes the Northern Lights?
- How Does a Mirror Work Exactly?
- How Does Gravity Affect the Moon’s Orbit?
- What Causes a ‘Golden’ Sunset or Sunrise?
- How Does Gravity Affect Space Travel?
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Categories: Physics · acoustics,sound waves,sirens,frequency,waves