I am using version 2.65. When I go into NLA Editor and click Add-> Add Sound Clip, it does not prompt me for a file like I expected. Object Tools in my 3d view does implicate I made an action, but not other indicator shows that Blender responded in any way. The only two buttons under the Add menu which do seem to have responses are “Add Transition” (which it appropriately gives me an error) and “Add Action Strip” which pulls up a search block. Is there something I am not doing right, or is there some reason that Blender is not responding as expected? I feel like this is an extremely stupid problem, but after a while I still haven’t figured out what is wrong.
I don’t think I’ve ever placed audio into the NLA editor, so couldn’t help you with that exactly (maybe someone else could?).
But you could import it into the Video Sequence Editor. Then in the timeline, click the “Sync Mode” drop down menu and change it from “No Sync” to “AV-Sync”. Then, additionally if you want to hear your audio with the Blender playback, you can select “Playback” in the Timeline’s menu and at the very top of the drop down, check the “Audio Scrubbing” checkbox.
Hope this helps