Sharon and David from Jivamukti Yoga would call these words 'at risk' because they have been so normalized in American yoga studios and their meaning has essentially evaporated. Words spoken without understanding the meaning is just sounds.

I pronounce it more like Ahhohhmmm.

There are three distinct parts:

To me chanting Om is about awakening the energy channels in the body, particularly sushumna nadi. Similar to singing, you have to really tune into the notes and vibrations to get the benefits.

Ah should vibrate from the pelvis to about the solar plexus.

Oh should vibrate the chest and throat.

Mm should vibrate the head and end near the roof of the mouth.

It's not actually that cut and dried, but it is an upward line from base of spine to crown of head.

If you think about an engine revving - VROOM:

We are revving our energetic system.

"The light in me sees and honors the light in you"