Linkina Media - Video Plays but Audio Doesn't

Hi there, have a problem that's got me scratching my head. 

I'm linking media - an interview with video and audio - that I transferred from an external drive to my own drive. The media turns from red to blue and the video appears but the audio doesn't. And although it seems premiere is recognizing the audio there's no waveform or anything there. The source has both video and audio working fine and I'm not having this issue with any other projects/sequences I've been working with. 

I'm stumped. Any ideas? 

Thanks!