85B.4  Definitions.
  As used in this chapter, unless the context otherwise provides:
  1.  “Excessive noise exposure” means exposure to sound capable of producing occupational hearing loss.
  2.  “Hearing level” means the measured threshold of hearing sensitivity using audiometric instruments properly calibrated to the American national standards institute audiometric zero reference level.
  3.  “Occupational hearing loss” means that portion of a permanent sensorineural loss of hearing in one or both ears that exceeds an average hearing level of twenty-five decibels for the frequencies five hundred, one thousand, two thousand, and three thousand Hertz, arising out of and in the course of employment caused by excessive noise exposure. “Occupational hearing loss” does not include loss of hearing attributable to age or any other condition or exposure not arising out of and in the course of employment.
[C81, §85B.4]
98 Acts, ch 1160, §2