Definitely a South American lungfish. The face is somewhat mangled, though. Stories like this come up all the time showing a species that many people have simply never heard of or seen and wild claims are made up about it. I have never heard of a lungfish making any sound, but I don't know that they are incapable of it. Either way, based on the source, they could have said it was speaking fluent Mandarin Chinese and I'd be no more skeptical than I already am.
Looking at the head structures, it's definitely a poor Lepidosiren paradoxa that had it's head bashed in and suffered wood dowels being inserted into its mouth to hold it's battered jaws apart.