Issues of the Syllable repetition

Hello,

I've completed my 5th session and I'm enjoying the meditation. I feel relaxed afterward. However, despite the manual's assurance that I can't be doing it wrong, I need a little more guidance on the repetition of syllable. On one hand, the manual says to repeat it, but on the other hand the third Lesson says that when returning to the syllable "do not start thinking it clearly".
Is this a contradiction?

Also, when I think of the syllable I tend to want to form it with my mouth. I stop myself from doing so, and I never repeat the syllable out loud, but there is a tendency to think it clearly.

Finally, I initially kept hearing the syllable in the woman's voice on the MP3 file, though now the voice is mainly my own. Does this matter?

Thanks for any advice,

Andrew