I do NOT believe that hearing does help drivers drive better, it is just hogwash. AND I can prove easily!
Too many people are talking on cell phone, this can distract hearing drivers!
There are cars that was built as sound proof from outside of cars because hearing people can't stand the noises from outside of cars, yet they still drive and can't hear from outside hence soundproofing cars. If hearing is so important, then why build soundproofed cars? Don't believe ones that exists? Here is the link
Are cars too well sound-proofed for drivers to hear emergency vehicles approaching? Text - Physics Forums Library which concerns about soundproofing cars with emergency vehicles! True business there is plenty out there.
What is most important part of driving? Of course your EYES! Without Eyes, you won't be able to drive, period.
finally there are plenty of people that cranked the volume up to the top in their cars, how can they hear from outside while inside the cars is damn too loud?
I think it is lame excuses for hearing people to look down at Deafies that they think can NOT drive just because they can't hear. FULL OF BALONEY!
Now you got my answer to your question!