What?
This post reflects my own aging, as well as the overall aging of our community.
Have you ever been in an audience, looking forward to a presentation, and ultimately you don't hear much of the presentation? Maybe you tried to hear to 
the speaker who started by saying "I won't be using the microphone today. I have a big voice so I'm sure you can hear me. Raise your hand if you can't hear me and I'll speak up."
What?
Even speakers with loud voices can be difficult to hear. Gilda Bonanna wrote " You may think, "my voice is powerful enough and I don't need it," but often, that is not the case. Realize that it may be difficult for the audience to hear you, given the size of the room and the amount of surrounding noise. Also, according to a 2009 study by the Better Hearing Institute, the number of Americans with hearing loss has grown to roughly 11 percent of the U.S. population - and six out of ten of them are below retirement age. So it is likely that there are people in your audience with some level of hearing difficulty. Article Source: http://EzineArticles.com/7806807
Join me in my quest to encourage all speakers to use a microphone. Raise YOUR hand and ask the speaker to use a microphone, even if you can hear the speaker. Chances are, there's somebody who can't hear well, but is reluctant to speak up.