Storyline with audio - accessibility options

Hi everyone, 

I am working on a project where the SME is insistent on audio narrated slides (only some not all slides have audio). I understand to meet accessibility standards we must include a way to turn off autoplay. I have done this using a variable - the user opts out of auto play at the beginning of the course. Essentially there is a trigger that says Pause timeline when the variable (Autoplay_off) is True. Then users manually control the audio using the player controls on each slide that includes audio. 

I am trying to include a tab interaction where the layers for each tab have audio. When the user has opted out of the autoplay I am not able to get the layers to play manually. 

Has anyone accomplished this in a way that meets accessibility WCAG 2.0 standards? I am totally open to suggestions or examples where you have used this. 

Thank you so much for your input.