FCPX no sound!
I've had this issue before. Trying to audition a clip and press the "I" and "O" before dragging an excerpt of the clip to the time line. Usually this procedure works fine. Today, there is no audio at all. But, if you drag the entire clip to the Time Line you hear audio.
I have a very vague recollection that this has something to do with the audio configuration of that clip. I've messed around with that a bit - but no luck.
Any ideas?
I've attached a screen capture for clarity.
MacBook Pro 15", macOS 10.14