I may understand your question differently from Rod's interpretation. Do you need to reproduce this same situation:
- one of the buttons is clicked
- the callout appears with the text
- at the same time the audio plays as well
Is this what you need? From the screenshot I deduct that:
- The callout is added by changing the state of the image. Check the Object state panel (State view button in the Properties panel of the image)
- That state has audio attached.
If you need to edit such a callout, first check the action attached to the button which makes that callout visible. That would confirm my suspicion. Maybe you can add a screenshot of that action?
In the object state panel you go to the custom state, replace the text in the callout, and replace the attached audio (Options tab). There is no automatic link between the text and the audio file. This is not really CC as is possible with the slide audio. It is a manual job, synching is done by using the state. Here is an example of a similar situation:
http://blog.lilybiri.com/click-slash-reveal-interactions-back-to-basics
However in that example I used the image as button, which is not the case in your situation where you use an extra button. Being able to use any image as button is new in version 11.5.