Here are some suggestions. You will need to tune this method, but it's better than no method.
Provided that you have the heat set correctly (see below), when the meat gets closer to being cooked (and as some of the water in the meat evaporates), the sound of the sizzle changes and you hear less sizzling and kind of quiet.
There is something to this. Often times when I'm away from the frying pan, I can hear the pan is ready or requires a stir since the sizzling characteristics change.
For strips of meat like stir fry and chicken strips, the pieces get less floppy as they cook. A piece of raw chicken dangles right off the cooking tongs whereas a properly cooked one holds firmer.
Finally, you can use time to cook to perfection every time. 3-4 minutes usually for minced meat, as long as you follow the same process. Here's an example from Cooks Illustrated:
Heat 12- or 14-inch nonstick skillet over high heat, 4 minutes (pan should be so hot,
you can hold your outstretched hand 1 inch above its surface for no more than 3
seconds); add 1 tablespoon oil (add 2 tablespoons for tofu or fish) and rotate pan so
that bottom is evenly coated. Let oil heat until it just starts to shimmer and smoke.
Check heat with hand. Drain meat, seafood, or tofu, then add to pan and stir-fry until
seared and about three-quarters cooked (about 20 seconds for fish, 60 seconds for meat,
2 minutes for tofu, 2 1/2 to 3 minutes for chicken). Spoon cooked meat or seafood into
serving dish. Cover and keep warm.
What you're looking for in the pan, is temperatures of about 350F. For your set up, I would highly recommend a quality infrared thermometer. This not to measure the meat (the surface won't say much), it does however tell you how hot the pan is, and you can easily establish how long it takes to properly cook 6 ounces of a meat. This does not require any visual inspection as long as the contents of the pan is moved around and a frying time table is follow.
I did hear (either Jack Bishop Cooks Illustrated, or Nathan Myhrvold) saying that it takes about 4 minutes to pan fry 1/2 inch depth of meat. I can't find the exact reference and values in my notes, but the point is that there is a deterministic solution to time to fry in a pan.