Why ohm? (See details.)

Eastern meditation seems to always involve a low, droning “Ohmmmmmm…” sound. Why ohm? I’ve done a bit of testing, and I can’t find anything that comes close to sounding as right. For instance. try close substitutes like:
    “I’rmmm…”
    “Ermmm…”
    “Ammm…”
    “Ahemmm…”
    “Ummm…”

None of those work nearly as well. But why? Is there something cosmically special about the name we in the West chose to attach to the basic unit of electrical resistance?