I agree that sidetone is a valuable aid to making the use
of a communications device seem more natural and intuitive.
Perhaps this should be a parameter that is user-adjustable
(at the risk of causing feedback if set too high).

I also agree that the fidelity and perceived audio quality
of small speakers leaves much to be desired. Perhaps such
sound quality is irritating to some people - but then some
are hypersensitive in general. Since I'm a daily user of
such devices, I tend not to notice. I have a "hands free" adapter in my
work vehicle, and agree that using it provides
a remarkable improvement in sound quality. However, I tend
to use the "hands free" feature only when stopped. If the
phone rings while I'm on the road I will invariably pick
up the handset.

I do think that us pilots are more able to use a cell phone
while driving than the average joe. This is probably because
we are accustomed to multitasking and prioritizing our
sensory inputs. That would make an interesting subject for
a study. As for the safety aspect, I am careful to pull
off the road before dialing. Answering or continuing a
conversation already underway requires considerably less
attention.
As for the helmet idea - I'm being facetious, of course!

David Johnson