What makes sounds have more volume (higher desibel)?



What makes sounds have more volume (higher desibel)?

In: Physics

In short: energy.

Slightly more explanation: the more energy you put into something, the greater the vibration of particles in the air, the greater the vibration of the bones in your ear, increased volume.

Sounds are waves which have two main properties; Frequency and amplitude. A higher amplitude means a louder sound, to give a sound a larger amplitude you have to put in more energy when making the sound. If you lightly pluck a guitar string the sound will be quiet but the harder you pluck it the louder the sound will be.

Sound is a wave of pressure in the air. That is, a series of high pressure and low pressure areas moving through the air. A louder sound will have a higher difference between the low pressure areas and the high pressure ones.

The lowest possible pressure a sound wave could hypothetically create is a vacuum and the highest is two atmospheres of pressure. This works out to approximately 194 dB.

We often think of sounds as waves wiggling up and down. Really, it’s more like the air is a stretched slinky, and sound is like giving one end a push and pull. This causes a ripple of forwards and backwards motion to travel along the slinky. The harder you push, the more extreme this ripple will be.

We hear sounds when this ripple travels into our ears and causes our eardrums to wobble in and out. If a more intense ripple hits your eardrum, the eardrum will move more. This extra wobbling gets passed along the middle ear to the inner ear, and the size of wobble makes a bigger signal go to your brain.

If you want more info about sound and hearing, [here](https://www.nottingham.ac.uk/research/groups/hearingsciences/ear-facts/ear-facts.aspx) is a website by the University of Nottingham. It was designed for kids, but has lots of interesting stuff 🙂