Fellow speaker,
To mike or not to mike, that is the question. Whether the audience can hear you without the microphone is the answer. If they can't hear you and you don't use a microphone then you have let the audience down...and maybe cost yourself a job! If you use a microphone and don't test it and there are problems with the audience hearing you then you have let the audience down...and maybe cost yourself a job! Remember both to mike if you need to mike, and to test your microphone before using it.
Bothing,
Tim
