Why high levels of noise affects all of us. David Baker explores how different sounds can impact on people without them even knowing and how to make our lives more tranquil. From the clangs and clatter of city life to weapons that use sound to harm us, noise can be a lot more dangerous than we think. But help is at hand from quieter underground stations to restaurants where the sound changes to reflect our moods and preferences.

(Image: Crowded, noisy, station; Credit: Shutterstock)