Loud and soft sounds
Bigger vibrations make louder sounds.
Loud or soft?
Some sounds are loud, like a crowd cheering. Some are soft, like a whisper. How loud a sound is, is called its volume.
The crowd at a big cricket match in Mirpur can be as loud as a lorry engine close by.
Bigger vibrations
Hit a drum gently and it makes a soft sound. Hit it hard and the skin vibrates more. The sound is louder. Bigger vibrations make louder sounds. The size of a vibration is its amplitude.
A guitar or ektara string plucked hard moves further from side to side. The bigger the movement, the louder the note.
Distance matters
As sound spreads out, it gets weaker. The further you are from a sound source, the softer it sounds.
When you are twice as far from a sound, it sounds much quieter, because its energy is spread over a much bigger area.
Loudspeakers
A loudspeaker has a cone that vibrates. It can make big vibrations, so the sound is loud. Turning up the volume makes the cone vibrate more.
Microphones and loudspeakers work in opposite ways: a microphone turns sound into electrical signals, and a loudspeaker turns them back into sound.
What I learnt
- I know that bigger vibrations make louder sounds.
- I know that sounds get softer further from the source.