If you click on "show background info" you'll see what data this demo is based on and what it does. The average 80 year old hearing is really scarily bad and I secretly hope that my demo is an exaggeration, but it is based on a peer reviewed study Lee
and colleagues http://www.ncbi.nlm.nih.gov/pubmed/15692300
which looks well conducted, so unless the population they had access to is somewhat unrepresentative of ... well .. us (clutching at straws
here?)... then I guess the answer is probably yes, if you live long enough the odds are 50% or more that your hearing will get really quite bad at the end.