Microphone Processor

To stabilize the voice of the speaker on a constant level, a Microphone Processor is necessary.
This is an audio compressor than can decrease the volume of the voice when it is too loud, or amplify it when
it is
too low.
Doing so produces a sound that captures all the details of the voice but
levels out volume changes.
Too high a volume level could distort the signal; or, if too low, it could make speech
incomprehensible.
A microphone processor helps smooth the audio, minimizes background noise
and cleans the signal.
It helps with the mixer control, since it is not necessary to continuously adjust the level of the
microphone.
It also helps to get "Radio Sound", so that it always sounds at the right level
and the speaker can concentrate on performance – rather than worry about
being too close or too far from the microphone, or even speaking in too
loud or too soft a voice.
Moreover, it gives more presence to the voice and allows to set it at higher level – because you are sure it will contain the peaks. Adding to it, it removes hissing noises such as those produced with words that contain an "s".
DBX 286 Microphone Preamp or Behringer Ultragain Pro MIC2200 are some of the most popular ones.