NEW YORK (Reuters Health) - Research suggests that prolonged exposure to loud noise increases the risk of acoustic neuroma, a benign tumor that grows in the nerve connecting the ear to the brain that is associated with hearing loss, tinnitus (ringing in the ears) and disequilibrium.

　　The only published study regarding noise and acoustic neuroma risk was limited by small size and its restriction to men only, Dr. Colin G. Edwards and colleagues note in their report, published in the American Journal of Epidemiology for February 15.

　　Edwards, from Ohio State University in Columbus, and colleagues at Karolinska Institute in Stockholm documented all patients diagnosed with acoustic neuroma between 1999 and 2002 in three geographic areas in Sweden. They interviewed 146 patients and 564 healthy control subjects regarding types and duration of loud noise exposure.

　　Exposure to loud noise, defined as that exceeding a level of 80 decibels, was associated with a marked increase in the odds of acoustic neuroma.

　　The categories associated with the highest risk were exposure to machines, power tools, and/or construction, and exposure to music, including employment in the music industry.

　　The authors observed that the risk associated with noise exposure was found in both men and women.

　　However, there was no risk associated with loud noise when hearing protection was used.

　　"The findings of an increased risk of acoustic neuroma with loud noise exposure support previous research," Edwards' group notes. They recommend additional research to validate self-reports of noise exposure and to examine the possibility of detection bias.