Audio works on Iphone/Ipad, but you must first pay around 3-6$ for one of the apps that works with an IP camera. The camera is viewable without an app, but the apps enable the sound/PTZ functions. Have not attempted anything on a mac.
i don't know if it;s the only way to do it but I can tell you it can be done using the FoscamPro App. The app is $599 but it's great and the one price enables it on my iPad and iPhone. (don't know about the Mac) Awesome app!
For your Mac, buy uFoscam at the Apple app store for $7. It will give you 2-way audio. It's really a very nice little program that will handle up to nine cameras. It also corrects a quirk with the pan on Foscam cameras using third party software whereby the left and right buttons work in reverse. This program has a setup feature that allows you to flip the control of the pan (and tilt) buttons).
For your iPhone or iPad, use Foscam Pro ($5.99), uFoscam, or IP Cam Viewer. All three will allow you to manipulate multiple cameras, watch streaming video, have 2-way audio, and record to the iPhone or iPad.