▁with ▁their ▁v ib rat ory ▁characteristics . ▁N od ules ▁may ▁increase ▁the ▁mass ▁of ▁the ▁vocal ▁fol ds , ▁especially ▁along ▁the ▁med ial ▁edge ▁where ▁they ▁are ▁typically ▁found . ▁This ▁increased ▁mass ▁may ▁result ▁in ▁a period ic ▁or ▁irregular ▁v ibration , ▁the ▁per ception ▁of ▁greater ▁pitch ▁and ▁loud ness ▁perturb ations , ▁and ▁of ▁increased ▁ho ars eness . ▁N od ules ▁may ▁also ▁affect ▁the ▁m uc os al ▁wave ▁of ▁the ▁vocal ▁fol ds ▁by ▁changing ▁the ▁configuration ▁of ▁the ▁vocal ▁fol d ▁closure ▁pattern . They ▁often ▁cause ▁incomplete ▁closure ▁of ▁the ▁vocal ▁fol ds , ▁resulting ▁in ▁an ▁hour glass ▁configuration . ▁The ▁incomplete ▁closure ▁allows ▁more ▁air ▁to ▁escape ▁through ▁the ▁vocal ▁fol ds , ▁which ▁often ▁results ▁in ▁the ▁per ception ▁of ▁breath iness . ▁The ▁degree ▁to ▁which ▁nod ules ▁will ▁affect ▁the ▁m uc os al ▁wave ▁and ▁v ib rat ory ▁characteristics ▁of ▁the ▁vocal ▁fol ds ▁depends ▁highly ▁on ▁the ▁size ▁of ▁the ▁nod ule . ▁Sm aller ▁nod ules ▁may ▁still ▁allow ▁the ▁vocal ▁fol ds ▁to ▁achieve ▁complete ▁closure . ▁ ▁Di agn osis ▁Di agn osing ▁vocal ▁fol d ▁nod ules ▁typically ▁includes ▁a ▁compreh ensive ▁analysis ▁of ▁medical ▁and ▁voice ▁history , ▁a ▁physical ▁exam ination ▁of ▁the ▁head ▁and ▁neck , ▁per cept ual ▁evaluation ▁of ▁voice , ▁and ▁visual ization ▁of ▁the ▁vocal ▁fol ds . ▁Visual ization ▁is ▁considered ▁to ▁be ▁the ▁main ▁method ▁of ▁diagn osis ▁as ▁per