I don't think there is audio in CS6, that was added in PS CC.
Im not sure. I mean it looks like you can edit video with Photoshop cs6, and with that there are two sound icons, both mutable. So Im guessing I should be able to here sound on my video. The two sound icons are not muted, and when I play the original sony a7r video on my computer there is sound with it (windows media player). The video format of the sony a7r appears to be avchd .mts format
I just tested this, and I guess it may have been CS5 that didn't have audio. I do have audio with CS6. The mute icon in my case doesn't turn the audio off. I'm not sure what's going on, if you are getting audio in other apps.
I found this in the Adobe help files...
"About video layers
You can use Photoshop to edit individual frames of video and image sequence files. In addition to using any Photoshop
tool to edit and paint on video, you can also apply filters, masks, transformations, layers styles, and blending modes.
After making edits, you can save the document as a PSD file (that can be played back in other Adobe applications such
as Premiere Pro and After Effects or accessed as a static file in other applications), or you can render it as a QuickTime
movie or image sequence.
Note: You can work only with the visual images in a video file, not the audio."