And OṀ is the name of God. OṀ is the name of Dattātreya. OṀ is the name of Gaṇapati, praṇava-svarūpa vakratuṇḍam.
It consists of three syllables. When you start saying OṀ it opens up the mouth - A U Ṁ. You have to open your mouth to say A. When you say U, then you have to say – make it round, open your lips, make it round, continue, Ṁ, internalize this. The sound U and Ṁ, continue as the sound, let us say, of a Vina string [which was struck] and after striking, then it continues as a sound. Whereas, we cannot say if it is AṀ, or IṀ or UṀ, or RṀ, or ḶṀ. So when the initial part, the plucking is taken away, the remaining part is indistinguishable, it continues like that.
So OṀ is supposed to be consisting of five letters.
A,
U,
M,
its continuation and
termination.
[These] five, they are called sṛṣṭi, sthiti, laya, tirodhana and anugraha.
Sṛṣṭi means creation [i.e. A],
Sthiti means sustenance [i.e. U],
Laya [destruction]. [i.e. M],
And continuation, tirodhana.
And anugraha, absence. It becomes zero, nil, quiet, attributeless.
So all of these five syllables are contained in OṀ. We are normally told that it consists of three syllables, but Śrī Vidyā extends the research further and says – yes, it has five syllables.