How to set up Cp 9 so user has to click button to hear audio

I suspect that you inserted the audio as slide audio. There are several ways to keep the audio from playing immediately:

• With slide audio, move the audio away from the start of the slide for 1 or 1.5secs, insert a (shape) button that has the command Continue, and pauses the slide at the same moment as the start of the audio. The advantage of this method is that you can use the same work flow on each slide, if you use a shape button timed for the rest of the project, always on top. You only have to move the audio clip on each slide.
• Not using slide audio, but audio attached to an 'invisible' object like a shape with a Fill at Alpha 0% and no stroke. Hide that object, and create a button that will show the object. When it gets visible, audio will play. In this case you'll need a different 'audio object' on each slide and a different button. You could use a shared action for the button or a simple action.
• Use a different button on each slide with the simple command 'Play Audio'.

To do this, I usually use an Interaction (either a Button or Click box, depending on my needs).

After adding the interaction, in the Properties, click the Actions tab, and then you will find a On Success drop-down box. Choose the "Play Audio" from the list, and then select your audio file just below the drop-down by clicking on the folder icon:

This way, the audio should not play during the timeline, and only after the learner has clicked the button/click box.

If you already have a shape created on your slide that you want to add this action, you can check the "Use as button" to show the Actions tab:

Hope this helps!