Noise can me more than a nuisance – it can be dangerous. Noise is a vibration of air molecules. If the noise is loud, the air molecules vibrate more violently. The vibrations can be violent enough to create a shockwave, as in an explosion or a sonic boom, but even less sever vibrations, of the sort experience everyday by pneumatic drill operators, can damage a persons hearing if experienced regularly.
Workers subject to prolongued periods of loud noise protect themselves by wearing earphones or earplugs. In the UK, the maximum noise level is 90 dB over an eight hour day, or 100 dB for 48 minutes. Many young people expose themselves to much louder levels of music at parties andf discos.
If your environment is loud enough for you to have to shout to be heard at arms length, then your hearing could be damaged. Hearing damage is permanent – the nerves in your ear are very sensitive and cannot be replaced.