[Bob Galteland]

Just some nominclature clarifications . . .
“Omni” is short for Omnidirection – meaning the mic is designed to pick up all sound from every direction fairly uniformly. Omni mics are not intended to have a tight pattern.
“lav” is short for lavaliere – which is the intent of the mic to be positioned generally in the upper chest/lower neck area.
“Cardioid” is another type of mic pick-up pattern, that has a definet direction and does not pick up sound from all direction evenly.

I Concur with Rodney’s recomendations. If you want to eliminate other sound you need to go to a lavalier mic with a cardioid pick-up pattern, or go to a headset type mic for even better rejection of background noise. A few years back we used a Sennheiser product with good success. I don’t think it’s made any more, similar to their ME4 product today.