The ads call them “invisible hearing aids,” describing them as “discreet,” “well-hidden” and “virtually undetectable.” Perhaps that sounds appealing, but it also sends an unintended and damaging message: Hearing aids are shameful and something to be hidden. You might as well wear a bag over your head. The ads also reinforce the notion that wearing hearing aids trumpets the fact that you’re old. Which is silly, as audiologist Mark Ross wrote in a recent column for hearingresearch.org, because “rejecting a …