Aside from speakers and an audience, microphones are the most important feature of any presentation. Unless you are in a very small room, every speaker will need some form of voice amplification in order to be heard clearly by every person in the audience.
Not surprisingly, microphones are also the items of equipment that are most likely to go wrong, developing unforeseen crackles or suddenly going silent. The more microphones you have the greater the risk of problems.
Talking to your AV company well in advance will help reduce the risk. They can advise on the number and type of microphones that should be used. A good company will also have spare microphones on the day ready to bring into use if an emergency occurs.
Take time to check out the venue with the AV company to identify any potential background noise, which might affect the acoustics. Does the room echo? Is there any noisy equipment that will be present? How good is the sound insulation? Are the proceedings likely to be interrupted by noises from outside the room? Microphones can be extremely sensitive and pick up even the slightest noise such as heating and ventilation systems. Testing in advance can make a lot of difference.
It is worth considering putting any noisy equipment in a separate room. AV specialists can take action to cancel out echoes, or reduce outside noise providing they have warning that this will be needed.
Then there are the speakers themselves to be considered. If wearing headsets or lapel microphones, they need to be warned in advance. Jingly earrings worn with a headset can cause extra noise and distract from the presentation. It is not unknown for speakers to turn up on the day wearing clothes to which microphones and battery packs cannot be fitted!
Microphones on stands or on tables need to be adjusted to suit the height of the speaker. Time needs to be allowed on the day to do this. It can take longer than expected, especially if someone is very tall or short. Speakers and performers also need time to practice with the microphone to make sure they are happy and that it picks up their voice effectively. Whenever possible, this should be done during a gap in the proceedings – after all, audiences can get very restless if they have to wait for any length of time.