After importing clips, and attempting playback, all is well. About 15-20 seconds into playback, the audio stops working. I can restart the clip, and start at any point and hear all the audio, but it continues to go silent after 15-20 seconds regardless of where I start playing, and is doing so in every video clip imported.
The only clips that play full audio & video for the entire duration are off the iphone/quicktime. The imported files are from a Canon Camcorder, .mts file extension.