Filming guitar instructional videos. Currently have a RODE NTG-1 mic positioned above and in front of the teacher. Problem is that the mic not only picks up the teacher's voice, but also the sound coming out of the monitor speakers, as well as that annoying pick snapping against the strings sound that makes the guitar sound thin and tinny on the video. Someone said I need to use a head/ear set mic to avoid this. What type should I be looking for so that the mic only picks up the voice and nothing else, or as little as possible of anything else?