AUS ADV Ocean Shield has been sent to the area, and has actually reported a pinger signal...
Marine Traffic
It has a Remus 6000 onboard (6000m depth) and a Triton XLS (4000m depth), both could be outfitted with a pinger sensor.
They also have at least one UUV onboard, which are completely autonomous, the Bluefin 21 has a working depth of 4500m. The US Navy provided a B21
This ship, the Swire Seabed, is the one that recovered the AF447 and the Atlas rocket engines.
Swire Seabed