(e) An additional amount of permanent partial disability shall be granted for impairment of speech discrimination, if any, to determine the additional amount for binaural impairment, the percentage of speech discrimination in each ear shall be added together and the result divided by two to calculate the average percentage of speech discrimination, and the permanent partial disability shall be ascertained by reference to the percentage of permanent partial disability in the table below on the line with the percentage of speech discrimination obtained. To determine the additional amount for monaural impairment, the permanent partial disability shall be ascertained by reference to the percentage of permanent partial disability in the table below on the line with the percentage of speech discrimination in the injured ear. TABLE
% of Permanent
% of Speech Discrimination Partial Disability
90% and up to and including 100% 0%
80% and up to but not including 90% 1%
70% and up to but not including 80% 3%
60% and up to but not including 70% 4%
0% and up to but not including 60% 5%