I'm not familiar that particular model. However, if the recording is in the AVCHD format, you would be using the Log & Transfer method rather than Log & Capture method as yo would be with DV or HDV.
In either case, is it possible that you may have overlooked checking the Import Settings in Log & Transfer or Clip Setting tab in Log & Transfer, to verify that both the Video & Audio checkboxes are ticked. If they are in fact checked, then I'd suggest you try bringing a clip into Mpeg Streamclip & converting it DVCPro HD & see if the resulting clip has sound.
All the best.