The National Fire Protection Association (NFPA) has a regulation that states: Hearing protection shall be provided for and used by all members operating or riding on fire apparatus when subject to noise in excess of 90 dBA. NFPA 1500(7.18.1)
So then either these four guys were issued faulty hearing protection, again not the engine manufacturers, or it’s a scam! Oh say it isn’t so, a scam by first responders!