(1) For the purpose of this section, "hard of hearing" is defined as inability of a subject to pass a voice recognition test or any equivalent test selected as appropriate by the Drivers License Advisory Board. A voice recognition test consists of a test of the ability to correctly identify four out of five numerals spoken in each ear with the examiner standing 2 feet behind the patient. An individual who habitually uses a hearing aid may wear it during the test.
(2) It is suggested that individuals whose cases are referred to the advisory board on the basis of hearing deficiency be grouped as follows:
(a) Became hard of hearing before the age of 15 years;
(b) Became hard of hearing after 15 years of age and has been aware of deficiency for more than 4 years;
(c) Became hard of hearing after 15 years of age and has been aware of deficiency for less than 4 years.
(3) In the absence of other adverse factors, individuals in all the above categories may be recommended for a Class A, B, C, or M license, with these restrictions.
(a) Those in groups (a), (b), and (c) above should drive only in vehicles equipped with 2 side mirrors in addition to any inside rear view mirror otherwise required.