Earplugs are a must for all those who want an up-close look at the race cars in the Grand Prix of Baltimore this weekend, health officials are warning. &quot;Using ear plugs preserves healthy hearing and doesn't take away from the excitement of the event,&quot;said the Baltimore City health commissioner,Dr. Oxiris Barbot. She said exposure to loud noises over an extended period of time can cause hearing loss. That includes IndyCar races, music concerts and other loud events. Hearing loss can affect people of all ages, according to the National Institute of Deafness and Other Communication Disorders. The groups says approximately 15 percent of Americans between aged 20 and 69 have some level of hearing loss that can be attributed to exposure to noises over 85 dB. Racing spectators are often exposed to noise above 96 dB to 110 dB, according to the National Institute of Occupational Safety and Health. Look for the information kiosks this weekend because Grand Prix organizers say they will be providing ear plugs. For more information on hearing loss prevention, go to www.baltimorehealth.org or www.nidcd.nih.gov.