Well I’m glad that you don’t find the point “incredibly offensive” (your words).
I didn’t say that you might develop additional senses (that would be a neat trick), rather that your remaining senses would presumably be better developed than might be the case in another individual.
I also strongly agree that no rider should ever be penalised for lack of care just for not being able to hear – but I do still think it is a good idea to do what you can to pick up little nuances of traffic behaviour and also to communicate with drivers where possible. When you commute a lot of the traffic is the same individuals coming past you every day – if you hear a certain car going a bit too aggressive one day (or see them, whatever), and you glance over your shoulder to remind them that you are there, then bit by bit you do as much as you can to keep safe.
Don’t be too passive, is what I’m saying. It was really the danger of putting on the iPod and switching off the brain that I was alluding to.