85B.9  Measuring hearing loss.
  1.  Audiometric instruments, properly calibrated to the American national standards institute specifications, shall be used for measuring hearing levels and in such tests necessary to establish total hearing loss, if any. The hearing tests and examinations shall be conducted in environments which comply with accepted national standards.
  2.  Audiometric examinations shall be administered by persons who are certified by the council for accreditation in occupational hearing conservation or by persons licensed as audiologists under chapter 154F, or as physicians or osteopathic physicians and surgeons under chapter 148, provided the licensed persons are trained in audiometry.
  3.  In calculating the total amount of hearing loss, the hearing levels at each of the four frequencies, five hundred, one thousand, two thousand, and three thousand Hertz, shall be added together and divided by four to determine the average decibel hearing level for each ear. If the resulting average decibel hearing level in either ear is twenty-five decibels or less, the percentage hearing loss for that ear shall be zero. For each resulting average decibel hearing level exceeding twenty-five decibels, an allowance of one and one-half percent shall be made up to the maximum of one hundred percent which is reached at an average decibel hearing level of ninety-two decibels. In determining the total binaural percentage hearing loss, the percentage hearing loss for the ear with better hearing shall be multiplied by five and added to the percentage hearing loss for the ear with worse hearing and the sum of the two divided by six.
  4.  a.  The assessment of the proportion of the total binaural percentage hearing loss that is due to occupational noise exposure shall be made by the employer’s regular or consulting physician or licensed audiologist who is trained and has had experience with such assessment. If several audiometric examinations are available for assessment, the physician or audiologist shall determine which examinations shall be used in the final assessment of occupational hearing loss.
  b.  If the employee disputes the assessment, the employee may select a physician or licensed audiologist similarly trained and experienced to give an assessment of the audiometric examinations.
  5.  This section is applicable in the event of partial permanent or total permanent occupational hearing loss in one or both ears.
[C81, §85B.9; 
81 Acts, ch 42, §1
]
98 Acts, ch 1160, §6
; 
2008 Acts, ch 1088, §81