An important part of communicating with your audience is facial expression. Whether you are singing or talking, part of your message is in your face. If the mike obscures your mouth, the observer misses your smiles, frowns and much of the emotion you are trying to convey. The mike works better when outside the plosive path which solves both problems of wind noise and visibility. Unless the intent is phallic symbology, get the mike out of your mouth. The most prominent part of the image should be your face, not the mike.
You are often likely to have people in the audience who are aging. When spoken or sung words are part of your message you want them to be understood. While many don’t like to admit it or are even unaware of it, as you age you loose hearing in the upper frequencies useful for hearing consonants. There is an unconscious tendency to correct for this by learning cues from lip movements. If a microphone is obscuring your mouth, or you are turned away, you are going to have reduced communication to some of your audience.
The working part of a condenser mike is smaller than a pencil eraser. It works fine except the first thing an engineer needs to do is cover it with a wind screen to hide breath noises from people who have the mike at their teeth. Next he’ll probably add a foam pop filter to prevent sounds from plosive consonants like p, t, s, etc. The mike doesn’t belong in the wind stream of the talker for this and other reasons. If you can keep the mike where it belongs, you may not need an obtrusive windscreen or filter.
Excellent locations for mikes are at or below the chin, to the side of the mouth or, especially for video work, overhead. Headset mikes are often excellent choices for performers and work well with radio links with or without earphones. Lavalieres are good to keep people from playing with the mike although you sometimes want closer proximity when PA systems and feedback are involved. Lavalieres may be sensitive to movement noise.
Ideal distances for a microphone are typically two to eight inches away. Since sound intensity follows a square law, doubling the distance to the mike reduces the level by four. Maintaining steady sound levels can be difficult if the mike is at short distances. Movement of a mike between one and two inches from the mouth will cause a much greater level difference (4:1) than moving between six and seven inches (1.4:1). A distance much over eight inches may tend to pick up ambient noise and room echo to an undesirable extent.
The axis of the mike should point toward the mouth. Most are directional and most sensitive in that direction. Off axis pickup (into the side of the microphone) may have shifted frequency response curves and lower levels. Sound can be picked up equally well from almost any direction in front of people and do not need to be directly in front of the mouth.
Moving very close to directional mikes can provide a bass boost. This is sometimes an intentional effect used by the performer, but in general, the frequency response desired should be selected by equalizer adjustments rather than mike placement.
Cupping your hand to the mike distorts the frequency response of the mike and increases sensitivity at some frequencies, just like cupping your hand to your ear. In PA applications it is likely to cause feedback. Covering a mike to reduce feedback usually fails since it makes it sensitive to certain resonant frequencies. Occasional feedback reduction can sometimes be accomplished by moving directional mikes further from your body or reflecting surfaces and/or pointing away from loudspeakers, toward a carpet or at a damping surface like clothing or curtains.
This generates noise by over-driving the mike; not good for the mike; not particularly pleasant to hear. Besides, the moisture is bad for the mike. Better to make an introductory comment or welcome which can serve as a sound level check.
Keep them well lubricated and not over tightened. Someone will always be fiddling with them. For varied users, it helps to have one person do all settings. Pointing the mike sideways and having the speakers stand beside the mike often works for various heights. A boom attachment to a mike stand can simplify height adjustments for varied users, especially children. Teach mike etiquette so people know where to adjust the mike.
A mike switch is the source of much agony. It is often in the wrong position and is always fiddled with. If you have someone operating the sound equipment, they should be the one to enable mikes and set levels. Eliminate the switches by bypassing them or taping them over. Momentary mute (cough) switches are useful in some situations.
Cable quality is something to pay attention to. They should be light and flexible. Good cables should produce no sound if you move or hit them (this and sounds from handling the microphone are called microphonics). You can get cables specially designed for flexibility and for low noise. If you have RF problems it is possible to get quad cables which are wired so interference in opposite pairs cancels out. If your performance style involves moving across the stage, have cables long enough to do the job. Intermittent cables are probably the most common sound problem, so spares might be useful.
Have you ever heard, “Can you hear me OK without this microphone?” An appropriate response would be “This is embarrassing but I am hard of hearing and ask you to please use the mike.” Most will respond in silence or not have heard the question because the mike was not being used. This is a form of glossophobia and needs to be overcome. The only one it benefits is the speaker so becomes a rather self centered request. It’s you afraid of the mike, not the audience. If someone has gone to the trouble of providing a microphone, it is because it is needed. Avoiding the mike interferes with recording and broadcast quality, reduces audibility in the back and balconies of rooms and halls, and blanks out hearing assist devices common to many sound systems.
If you expect audience participation, you should repeat any questions or responses not directed at the mike. You may want to plan on a mike or wireless mike to be used and will probably need an attendant to deliver it. Again, reiterate the response to make sure it is heard.
Having and taking your mike with you is an appropriate part of performing. Just as a professional violinist does not perform on just any instrument provided, a microphone is the performance instrument with its own response curve and familiarity. My recommendation is that a performer arrange time at a recording facility and test using an array of microphones, one directly in front of the mouth, one at the side, under the chin, overhead, some at a distance, a head-worn, a lavaliere, etc; omnidirectional, cardoid, supercardoid. Record all on multi-track for a test performance (including typical movement), listen and judge each one to gain confidence about what you can get away with and how you sound. You may be surprised at what matters and doesn’t matter.
You also need to try a variety of microphone brands and models. Each has its own response curves and you need to find which ones you prefer. Then invest in your own personal choices to take with you for performances. You may want to invest in both a cabled and a wireless mike. Make sure to carry all the appropriate accessories like the stand adapter, cables, batteries (fresh and spare), adapters to connect to XLR, 1/4” phone, 3.5mm phone connections, and probably a battery powered phantom power adapter. And remember you don’t want an expensive studio mike for a rough and tumble rock concert.
You will probably find a favorite mike after a short time. There are some models which are classics, and for a good reasons. They are popular response curves, dependable suppliers, rugged construction, good design, economical. Its likely you will find a classic condenser cardioid the most flexible and useful. My favorites are Shure microphones and Mogami cables. Their web sites are good educational sources.