I did similar long baseline acoustic localization for my dissertation a few years ago. We had about 15 microphones deployed in a wetland for bioacoustic monitoring.

https://resenv.media.mit.edu/pubs/theses/Resynthesizing_Volu...

Rather than manually finding the timestamps in the individual audio files you can do pretty well with using cross-correlation to find the relative delays between the mic signals. Any particular delay between a pair of microphones corresponds to a hyperbola through the mic array. If you visualize the hyperbola from all the pairs of microphones, the correct location pops up as the intersection of them. The cross-correlation peak can get pretty smeared out though, because each microphone is hearing a different version of the source signal.