“I think once you know how to recite the Praṇava
orally you will be able to do it silently.
And perhaps each time you can add a little meaning
to it as well as find a little more meaning in it.
The best way is to begin orally and
then transfer it to a mental recitation.
Then you can easily use it in your Yoga practice.”
– TKV Desikachar Religiousness in Yoga
‘Various Approaches to Yoga’
Chapter Seventeen Page 238