(1) For the purpose of this article -

"the better ear" means that ear in which the claimant's hearing loss due to all causes is the lesser;

"the worse ear" means that ear in which the claimant's hearing loss due to all causes is the greater.

(2) Subject to sub-article (3), section 75(4) shall have effect in relation to occupational deafness.

(3) The extent of disablement in respect of occupational deafness shall, subject to such adjustment as may be reasonable in the circumstances of the case, be assessed at the percentage calculated by applying the formula set out in Part 2 of Schedule 5 to the percentages specified in column (2) of Part 1 of Schedule 5 opposite the appropriate amount of hearing loss in the better ear and the worse ear respectively specified in column (1) of Part 1 of Schedule 5, being the total hearing loss due to all causes, measured in each case by pure tone audiometry over the 1, 2 and 3 kilohertz frequencies.