How do you recite ohm mantra?

O-HH-MMMS repeat this mantra and try to relax this mantra is designed to block bad chi in an attempt to recover healthy thoughts or atleast that is what i use it for i believe it is based off of the Word in physics for resistance also known as ohms so anyways it can be used during meditation as well just make this sound but let the sound resonate saying the Word but then closing mouth for greater resonation