I came across this cool piece of data today. It's a chart showing what happens to the frequency response of a voice when a lavalier microphone is placed in various locations.
The forehead placement sounds about like you hear a person sound if you are standing in front of them.
What is interesting is that almost every other placement results in sound that needs to be compensated for. And if you are in a noisy environment or have a soft speaker, you may miss something.
This is why I personally always try to use an external boom microphone in interviews or other sound capture situations. I place the microphone overhead and slightly in front of the person, just out of camera view.
This has two effects.
1, it results in the cleaner frequency response you see in the forehead mounted mic.
2, the microphone is a better quality mic, which picks up more audio information in general, resulting in a cleaner, better sound. I then can do some manipulation with EQ and various de-noise filters if needed, but the sound starts out better.
Using a microphone like this also has the benefit that you don't need to try to hide the microphone on the person, and that you don't need to mic them up, which can be somewhat time consuming and embarrassing for the interviewee.
Picking up clean, accurate sound is key to capturing great video. If you can't hear the person well, it doesn't matter how good they look!
As always, if you need to capture an interview or any other video, give me a shout!