(820 ILCS 310/7) (from Ch. 48, par. 172.42)
    Sec. 7. If any employee sustains any disablement, impairment, or disfigurement, or dies and his or her disability, impairment, disfigurement or death is caused by a disease aggravated by an exposure of the employment or by an occupational disease arising out of and in the course of his or her employment, such employee or such employee's dependents, as the case may be, shall be entitled to compensation, medical, surgical, hospital and rehabilitation care, prosthesis, burial costs, and all other benefits, rights and remedies, in the same manner, to the same extent and subject to the same terms, conditions and limitations, except as herein otherwise provided, as are now or may hereafter be provided by the "Workers' Compensation Act" for accidental injuries sustained by employees arising out of and in the course of their employment (except that the amount of compensation which shall be paid for loss of hearing of one ear is 100 weeks) and for this purpose the disablement, disfigurement or death of an employee by reason of an occupational disease, arising out of and in the course of his or her employment, shall be treated as the happening of an accidental injury.
    (a) Loss of hearing for compensation purposes shall be confined to the frequencies of 1,000, 2,000 and 3,000 cycles per second. Loss of hearing ability for frequency tones above 3,000 cycles per second are not to be considered as constituting disability for hearing.
    (b) The percent of hearing loss, for purposes of the determination of compensation claims for occupational deafness, shall be calculated as the average in decibels for the thresholds of hearing for the frequencies of 1,000, 2,000 and 3,000 cycles per second. Pure tone air conduction audiometric instruments, approved by nationally recognized authorities in this field, shall be used for measuring hearing loss. If the losses of hearing average 30 decibels or less in the 3 frequencies, such losses of hearing shall not then constitute any compensable hearing disability. If the losses of hearing average 85 decibels or more in the 3 frequencies, then the same shall constitute and be total or 100 percent compensable hearing loss.
    (c) In measuring hearing impairment, the lowest measured losses in each of the 3 frequencies shall be added together and divided by 3 to determine the average decibel loss. For every decibel of loss exceeding 30 decibels an allowance of 1.82% shall be made up to the maximum of 100 percent which is reached at 85 decibels.
    (d) If a hearing loss is established to have existed on July 1, 1975, by audiometric testing the employer shall not be liable for the previous loss so established nor shall he be liable for any loss for which compensation has been paid or awarded.
    (e) No consideration shall be given to the question of whether or not the ability of an employee to understand speech is improved by the use of a hearing aid.
    (f) No claim for loss of hearing due to industrial noise shall be brought against an employer or allowed unless the employee has been exposed for a period of time sufficient to cause permanent impairment to noise levels in excess of the following:
          Sound Level DBA
          Slow Response             Hours Per Day
               90                         8
               92                         6
               95                         4
               97                         3
              100                         2
              102                         1-1/2
              105                         1
              110                         1/2
              115                         1/4
This subparagraph (f) shall not be applied in cases of hearing loss resulting from trauma or explosion.
    In addition to discharging the foregoing obligations, the employer shall pay into the Special Fund created under paragraph (f) of Section 7 of the "Workers' Compensation Act", the same amounts and in the same manner as is provided in the same Act in cases of accidental injuries arising out of and in the course of the employment.
(Source: P.A. 81-1482.)