Wear hearing protection when exposed to loud noise. Earplugs are a must in noisy environments such as rock concerts and sporting events. They should also be worn when riding a motorcycle or snowmobile, mowing the lawn, using power tools, etc. If your job exposes you to loud noise, your employer is required by OSHA to supply hearing protection.
Turn down the volume. When listening to music or watching television, keep the volume low.
Limit the number of noisy appliances running at the same time.
Buy quieter products. Many appliances list dB ratings in their specifications.