Before you rejoice at this amazing ability whales apparently have, make a mental note of the following:
1. Marine Mammal Research Program at the Hawaii Institute of Marine Biology has been and still is basically a major playground for the majority of Navy funded research that constitutes the majority of research on marine mammals hearing worldwide. This place is the embodiment of the royal, most profound conflict of interest that ever existed. Pick randomly any publication produced by this place and check the funding source. Here you go.
2. The timing is not coincidental. The Navy is about to get a permit for insane range increase both in Hawaii/Cali/Atlantic Coast and worldwide. So the study comes at the best possible time for the Navy.
3. The sample size n=1. The subject is a long-time suffering false killer whale called Kina that has been a sole subject to a battery of tests and studies done in Hawaii in regard to hearing. Important to note that Kina’s hearing is most likely than not is completely messed up and does not represent hearing found in free-ranging false killer whales. Why? Because hearing thresholds of 9 bottlenose dolphins that have been housed in San Diego Navy’s facility and also have been studies subjects are completely messed up if not entirely %^&*-up (Schlundt et al., 2008)

Poor 20 y. o. Kina, a long-suffering false killer whale that has been a subject to dozens of hearing related studies, the Navy/Big Oil love to cite on their permit applications. Source: http://www.redorbit.com/images/pic/28975/jeff-pawloski-a-researcher-at-the-hawaii-institute-of-marine-biology/
Now to the study itself. In a nutshell, the major thinking the team had is that dolphins’ clicks are loud. So they were thinking what can dolphins do to adjust to such loudness when they produce these loud clicks? In a previous study funded (not surprise) by the Office of Naval Research Grant it was found that when a dolphin echolocates some sort of gain control occurring that modifies its hearing by making it (temporarily) less sensitive to loud echolocation sounds (link). Hawaii lab got all excited and moved to another stage, which is this study, where they trained long-suffering Kina to “reduce its hearing sensitivity when warned that a very loud noise is about to arrive” (link). How exciting! Now the Navy and Big Oil can blast everything in the ocean with the oldest sounds possible without feeling bad about it or being dragged to court by NRDC.
The research team cannot contain its excitement and brags about the discovery all over the media (link, link and link). The Navy is very happy too, money were spent not in vain. Now they can cite this study to death in every application for sonar permit. Big Oil is excited even more. Now Hawaii lab will get a huge grant from biggest noise polluters to come up with a warning ping that will warn cetaceans about sonar/airguns noise. The problem is solved.
Or is it? Sure blue whales calls are loud and dolphins echolocation is loud too. Sure partially deaf Kina can adjust whatever she can including her hearing so she does not go insane after all these years of sound torture. But something just not right. Here is why:
1. Cetaceans have been historically hunted with sound. It is still going on today. Read this article for good overview. If they can adjust their hearing as easily as Nachtigall & Co argues, why wouldn’t they just do that, and nobody could hunt them anymore? Right? Wrong, they do not do that and that is why they are still being hunted with sound even today, and this sound of banging on metal pipes is not even remotely as loud as sonar or airguns.
2. If the whales and dolphins can adjust their hearing and do that all the time in the wild they would not fear earthquakes. The quakes would be not a big deal, dolphins and whales would just adjust their hearing and go on their merry ways. But we have the evidence that point overwise. A fin whale was fleeing the quake site (link)
This is your typical Navy funded study. Take half deaf/half insane false killer whale that has been tortured for decades in a lab. Force her (aka “train” her, or she will not be fed) to do something and claim the victory with a whooping sample size of n=1 and transfer this findings to the wild populations. Give the Navy/Big Oil something to cite on those permits applications. In a mean time, ignore all strandings, do not investigate anything, do not search for any evidence. And most importantly have zero independent scientists (aka not funded by the Navy/Big Oil) working on a same issue. How &*^%$&* sweet!
EDIT (07/26/2012): Previous study published in 2005 in fact admitted that Kina indeed had been experiencing hearing loss:
References:
Schlunndt et al., (2008), Evoked Potential and Behavioral Hearing Thresholds in Nine Bottlenose Dolphins, Paper Presented at the Acoustic 2008 Conference, Paris, 2008.