Our dogs ride in kennels when we are driving anywhere ... It may not as much fun for them as riding "shotgun" but definitely a lot safer! If you insist on them riding in the cab with you, I would be more concerned about bugs, dust, stones and general crap getting their eyes, ears, etc rather than them becoming deaf from this.
NMH GMHR-IIII UH Dakota Creek's Royal Navigator MH (AKC & CKC) (NAHRA 500 pt club)
MHR Pine Acre's Dakota Sand Creek SH WCI
MHR-I UH Dakota Creek's Royal Gem
WR Dakota Creek's Wreaking Havoc SH
Dakota Creek's Cute As A Bug