I had to cut back on the 'IAM' mantra for a bit as my old pattern from twenty years of on and off meditating--- just counting to ten repeatedly--- is, for some unknown reason, forcing itself to the forefront of my mind. For awhile I felt a bit like a traitor to AYP not being able to maintain, but I'm sure it will come back to me when 'its' ready. Till then I wait and try to do everything else suggested. Still so glad to be connected with this site... Thanks, L
Just treat it as another thought. Let it play out if it is dominant. I had a similar situation, instead of trying to get back to the mantra as an internal sound, instead just hold the idea of the mantra as a space outside of the 1 to 10 repetition and drift gently towards it by putting your awareness there (you know it contains the mantra because you created the space). Then you can let your other mantra play out while putting attention on the place where the 'I am' mantra resides without it conflicting.
Eventually it bursts through and then maybe the other mantra comes back for a time.