Would you rather be heard, or be able to read your notes?

That’s not a pleasant choice! Please check out the whole room setup before you speak - including both sound and lights.

If the light on that lectern needs to be on for your speech, then check to see it doesn’t generate a buzz that interferes with the microphone. Things might have been fine until when the incandescent lamp burned out, and it got replaced by a compact fluorescent bulb, as was discussed by a 2007 article in EDN magazine.

Images from the History of Medicine showed Margo Heygood speaking at the 1976 NIH Conference on DNA.