Professional presenters

Once again I am astounded by the lack of care some professional presenters make to engage their audiences Yes, the content is valuable, yes the audience is adult, and yes, the audience is professional, but, honestly , as professionals involved in education, have we learned nothing about how people learn best?
People include the professionals. Attending a hui recently made me wish I was somewhere else assimilating the knowledge. Some presenters, following on from each other had lulling voices, the type that mother would use to send you off to sleep after a tiring day.
The content of their messages was important but I bet I missed 50% of it! Mental zzzzzzz, even if the body was awake!