H. S. Lewis - Aum Om Amen - The sound “Aum”
Analyzing the word "aum" as the more correct of the three syllables, we find that each of the three letters composing it has a power and mystical importance of its own.
The "a" sound is associated with the basic powers of the psychic nature, and of the physical body and physical world. For this reason we find the "a" is often associated in mystical ritualism with the following expressions or ideas: Brahma, Father, Harmony, Omnipresence.
The "u" sound comes from the center of the psychic body and is very closely related to the pituitary and pineal glands. It has a very definite effect upon them. But this is not true if the "u" is pronounced alone and separately as in the English language where we pronounce it like the word you.
When associated with the letter "a" as "ah" the "u" should be very soft and in the form of "oo," as in the English word mood. This gives you the double sound of "ahoo" with the accent on the "ah," and the "ah" sound drawn out slightly and ending with the sound of "oo." The letter "u" in this tone and manner of application is associated in ancient rituals with the words Vishnu, mind, light, son, and omnipotence.
When we add the sound of "m" we are drawing upon the vibrations from the tip of the tongue, so to speak, and bringing the other two to outer expression. By prolonging the "m" into a long humming sound at the end of a word, we are adding the significance of "m" which has always been associated in ancient literature with the Holy Ghost, with spirit, love, the psychic body, Siva, the dream state, passivity, and omniscience.
Analyzing all of these facts we see at once that the word is, after all, another and a very universal name for God, or the Almighty. This is why in the early Christian literature Jesus was referred to as "The Amen." Instantly we realize that the use of the word "Amen" in the Protestant Christian churches at the end of prayers or glorious expressions to mean "so mote it be" is erroneous.