Interviewers introduced these questions on firearms by stating, "The next questions are about your current or previous exposure to loud sounds or noises." Interviewers asked, "In the past 12 months, about how many rounds have you fired?" The survey form directed interviewers to read categories if necessary and to include target shooting, hunting and occupational experiences (military service, etc.). Further, the survey form advised that, "One round equals one shot."

Values were reported in categories as follows:

• None

• 1 to less than 100 rounds

• 100 to less than 1000 rounds

• 1000 to less than 10,000 rounds

• 10,000 rounds or more

This variable was part of the 2007 Supplement on Hearing, which included topics such as hearing rehabilitation services, the use of adaptive hearing devices, the frequency of hearing examinations, and hearing loss related to noise exposure.