(a) The hearing need not be conducted according to the technical rules of evidence relating to evidence and witnesses. Any relevant evidence shall be admitted if it is the sort of evidence on which responsible persons are accustomed to rely in the conduct of serious affairs, regardless of the existence of any common law or statutory rule which might make improper the admission of such evidence over objection in civil actions, except that the rules of privilege shall be effective to the extent that they are otherwise required by statute to be recognized at the hearing.

(b) Hearsay evidence may be used to supplement or explain other evidence, but shall not of itself be sufficient to support a finding. An objection is timely if made before submission of the case.