Objects all play when opening a project

Have a look at:

http://blog.lilybiri.com/pausing-captivates-timeline

Could you please clarify the issue a little more? Are you saying that on opening the project in a browser all of the audio clips for slides begin playing at the same time?  Or are you saying that the audio on each slide begins playing as you get to the slide and does not pause until transitioning to the next slide?

If the issue is the first one (all playing at once), I have never seen this.

If the 'issue' is the second one, where each slide's audio plays without pausing, then all you need to do is place an interactive object on the slide to pause the timeline.

Are you new to Captivate?  Have you done any training or watched any tutorials about how the Captivate timeline works?