A license holder shall try to obtain, personally or through a proper referral, at least the following information on each prospective candidate for amplification:
(1) the candidate’s pertinent case history;
(2) otoscopic inspection of the outer ear, including canal and drumhead;
(3) evaluation of hearing acuity using pure tone techniques through air and bone conduction pathways through a calibrated system;
(4) an aided and unaided speech reception threshold and ability to differentiate between the phonemic elements of language through speech audiometry, using a calibrated system or other acceptable verification techniques; and
(5) verification of satisfactory aided instrument performance by use of appropriate sound-field speech, noise, or tone testing, using a calibrated system.