Americans celebrate the Fourth of July by enjoying noisy firecrackers, concerts and parades - but at the risk of hearing loss, according to Robert W. Sweetow, PhD, director of audiology at the department of Otolaryngology/Head and Neck Surgery, UCSF Medical Center.
Noise from a firecracker, even at what might seem to be a safe distance, can lead to hearing loss in just minutes, he said.
In the workplace, the Occupational Safety and Health Administration mandates a noise level of no more than 90 decibels for an eight-hour period for employees without protection gear. According to Sweetow, every five-decibel increase in noise level requires that the time period exposed be cut in half. A noise intensity of 126 decibels, often produced at rock concerts, can cause damage in less than two minutes, he said. Fireworks can produce up to 150 decibels if one is within three feet of the source.
About 28 million Americans, or 10 percent of the nation’s population, suffer from hearing loss. It’s estimated that 10 million to 17 million of these people sustain at least a portion of the damage from noise exposure, said Sweetow. Gradual deterioration of hearing over several years that occurs due to excessive noise is called “noise-induced hearing loss.” A sudden loss of hearing from a single incident is called “acoustic trauma” and can be temporary or permanent.
Sweetow said mild hearing loss as a child or young adult may set the stage for significant premature hearing loss. Some studies suggest a “damaged-ear” theory, proposing that even minor hearing damage at a young age may make a person more susceptible to permanent loss, he said. Minor damage may become major damage when combined with the effects of age, disease, drugs and noise exposure over the years. Hearing loss can be accompanied by balance problems, permanent ringing in the ears and headaches.
Noise-induced hearing loss can be prevented by taking precautions on July 4th, Sweetow said. He provided the following suggestions:
· Wear earplugs when going to rock concerts or fireworks exhibits. Earplugs, properly worn, can reduce noise by 15 to 30 decibels.
· Keep as much distance as possible from the sources of noise, such as fireworks and amplifiers at concerts.
· Protect children by avoiding loud noise. Minor damage at a young age can lead to major hearing loss.
· Avoid prolonged periods of loud noise. If one’s ears are ringing or hearing seems dulled, it’s time to take a break. Even short breaks can reduce the chance of permanent damage.
For information about hearing loss evaluation and treatment, contact the UCSF Audiology Clinic of the UCSF Medical Center and UCSF Department of Otolaryngology/Head and Neck Surgery at (415) 353-2101.