Is it harmful to stick a speaker in your ear canal?

by Courtney Banks @ WSJ.com

[2:10] "..And I had to wonder, is it realy safe to stick a speaker so far in your ear canal? And If your ear is sealed, won't the soundwaves get trapped in there? So I spoke with Dr. Bill hodgetts, an audiologist at the University of Alberta. He explained that DECIBELS ARE DECIBELS whether they are coming from inside you ear or outside your ear. When earphones help block out surrounding noise, they let you listen to your music comfortably at a lower volume. That's what really counts for hearing safety..."

Yes, decibels are decibels.