I would have posted a separate Discussion, as your question is not directly tied to the Audio Mixer.
I will try to Branch this Discussion, to see if I can get it separated.
Now, while I struggle with that, my suggestion would be to Zoom into the Timeline View. That will enlarge things horizontally, making it easier to see. Next, look at the Track Headers (the Audio and the Video Tracks, where their names are), and find the little line at the top of your Audio Track, where your Clips are located. Hover your Cursor over that line. Initially, it might take a bit of hovering to find the "hot spot," but the Cursor will change to a equal sign w/ up/down arrowheads. When it does, click+drag up, to Zoom your Track's display in the vertical. This will give you a better look at the Waveform Display, where you should be able to see the peaks better. How much better, will likely depend on the Levels of your Audio.
Good luck, and let's see if I can Branch this for you.
Looks like Branch worked OK.
I sent you a PM, with the link to this Discussion, so that you do not think that your post disappeared.
Thanks for answer - this has sorted out problem.
Great news, and thank you for the feedback.
Hope that I did not confuse things too badly. Sometimes, Branch does not work, as it should.
Good luck, and happy editing,