Given the terrain of the focused search area is reportedly so tricky, it does lend some credence to the reasoning as to why nothing has been found to date. If this area is one of those known to be extremely mountainous (and there's no reason to believe it is not) then I'm (at last) hopeful some real progress is now possible.
Searching in and around a 5-6km sq targeted area seems eminently more likely to turn up "something", than tooling around 6000km sq (or whatever the most recent search area was supposed to be.
Given the (somewhat) limited knowledge I have of acoustics processing, it does not surprise me that it would take a very long time to re-process the original acoustic data - I imagine there were hundreds of hours of recordings, and processing that amount of data would be time consuming.
- GY
