Your primary revenue generating tool as a professional speaker, is your voice. Most of us, however, don’t really take care of our voices and that’s where we can run into trouble.
About a year ago I was giving a speech to a room of about 150. Intros went great, the opening got everyone laughing and focused. As soon as I got into the meaty part of my content – the lav microphone started crapping out. It would intermittently cut in and out. The AV folks ran over to install a fresh set of batteries – which fixed the problem. For a few minutes. Then I started sounding like a remixed version of T-Payne again.