(a) In all claims for occupational hearing loss caused by either a single incident of trauma or by exposure to hazardous noise in the course of and resulting from employment, the degree of permanent partial disability, if any, shall be determined in accordance with the provisions of this section and awards made in accordance with the provisions of section six of this article.
(b) The percent of permanent partial disability for a monaural hearing loss shall be computed in the following manner:
(1) The measured decibel loss of hearing due to injury at the sound frequencies of five hundred, one thousand, two thousand and three thousand hertz shall be determined for the injured ear and the total shall be divided by four to ascertain the average decibel loss;