Microphones are like magic. Along with an adequate PA system, they let you take something that’s not-so-loud and make it louder. Hooray! You no longer have to yell until your vocal cords shoot out of your neck just to tell Randy from accounting that your department had expenses that he can clearly read off the freaking paper right in front of his face.
It’s for this magical reason that vocal coaches often tell people “let the mic do the work.” For sure, that’s important – if you amplify somebody who’s yelling, it’ll just sound like loud yelling, and depending on the system (or engineer) it may just sound like distortion (here’s an example of mic distortion and giggling metal people). When you’re giving a speech, you definitely want to sound human and normal, so you should be a little quieter and let the mic take care of the loudness.
But, microphones have a dark side. As anyone who has had to make a heartfelt speech at a microphone in a movie knows, microphones can cause feedback (especially when it’s awkward), a sound that makes you want to rip off your ears and set them on fire. I think everyone knows the sound, but just in case you want a reminder, here’s 12 hours of it. Enjoy.
Put very simply, feedback happens when you turn a microphone up too loud, or when you get that microphone too close to the speakers. It’s generally pretty avoidable by just not doing those things, but that’s often a problem. If the person speaking is too quiet, the only way to get it loud enough is to turn it up, and sometimes that means I have to turn it up so high that feedback happens.
Related to this problem is if someone holds the microphone too far from their face – the closer you are to the mic, the louder it gets. Even if you’re yelling but are 10 feet from the mic, when I turn it up enough to pick you up, there will be feedback.
Very few people will naturally yell when they have a mic in their hand. I get very angry when I hear people say “let the mic do the work,” not because it’s wrong, but because they’re usually telling someone who is a naturally quiet speaker, who actually needs to do the opposite – they need to help the mic be ABLE to do the work. In ALL cases, when you’re speaking at a microphone, you should speak louder than you would in a conversation – theatre people call it “projection.” Don’t get so loud that your voice sounds harsh or yell-y…
…but be loud enough that if the mic suddenly broke, a good chunk of the audience would still be able to hear you.
If you get loud enough that you should legitimately “let the mic do the work,” not only are you in the maybe 1% of people who already know how to project, but your sound guy will definitely tell you. Otherwise, ignore those people and, for my sanity, please be louder.