What causes static only at the beginning of slide narration?

[pianopoint]

I am narrating a Powerpoint presentation. It is very clear, except for the
beginning, before the voice recording, where there is a brief static sound.
How can I eliminate this? I have tried without a microphone and with 2 types
of microphones, changing the quality and the volume.

 

[Eric Schmidt]

Hello pianopoint,

I have also run into this same problem.

First of all, what kind of microphone(s) are you using? I've discovered that
the quality of the microphone makes a difference.

Second, you might try to create some "sound baffling" around the microphone.
I know it sounds goofy, but I find that if you surround the mic with a
crumpled napkin and raise the volume slightly, you can get rid of the
background static noise at the beginning of the recording.

Even though I don't normally answer peripheral-related questions like this,
I hope that this helps you!