What Causes the ‘Hum’ in a City at Night?

Imagine a giant, invisible drum that’s constantly being tapped, this is what causes the ‘hum’ you hear at night. Big machines like traffic lights and power plants are like these drums, and they vibrate when they work, making a soft sound that you can feel in your chest.

Take the quiz →

Examples

A big traffic light in your neighborhood is like a loudspeaker that never stops talking.
The hum might feel like you're sitting next to a giant fan that’s always turning slowly.
You can sometimes hear it better when you’re lying down or resting.

Ask a question

Discussion

Recent activity

Categories: Environment · sound,city life,acoustics