In my experience in speaking in tongues in the baptism in the Holy Spirit, I exercised absolutely no control over what my mouth was doing. It was the Holy Spirit speaking, not me.

I had surrendered and submitted myself to God's Lordship, and I, finally accepted by Him, felt my bowels flooded with Life. That Power welled up within me until it reached my mouth, and that Power then TOOK OVER my mouth and spoke by it. By me. I had no control over it, and made no effort to direct it; I simply OBSERVED it. I did sense it was expressing the gratitude and appreciation and love for God I was feeling in my heart. Other than that, I understood not a word of it.