To summarise, the 37KHz pings heard near the surface (if true) indicate that wreckage is on the bottom somewhere nearby.
It is not, however, a simple job to narrow the search and determine an exact location because the signal could have bounced around in an underwater mountain range and been deflected by temperature and salinity layers.
The next part of the job, therefore, is to get listening devices as deep as possible whilst avoiding collision with the mountains. This requires specialist kit and is not easy.
This is going to take time and the batteries are nearing their end. It is therfore likely that a deep water sidescan survey will be required, the good bit is that the search area is now much smaller.
When wreckage is eventually located it will still take months rather than weeks to recover anything using UAVs