Narration option with timed objects

Question: How do I keep the slide from starting until the learner makes a narration on or off decision?

Background: I need the audio to not play automatically -per 508 requirements. I've tried to use Variables and Triggers to allow learners the option to have the audio on or off. The issue then becomes the slide animation which starts as soon as the slide appears. So, because the default of the narration must be off, if the learner decides he/she wants audio, the timing of the audio and animation will be off.   Slides are set to advance "By User". 

Please help as the lesson has 78 slides and all have animation in which the narration and images/content were synced.