Re: wild dolphin seeks out human help
I was thinking about the encoding, and not the range. There is more than one way to embed a meaningful thing in a sound. Some of the known ways to do so are impossible to interpret or detect without a common reference, but thankfully those are always artificial and not something you'd see evolving naturally. It could still be something pretty elusive, though.
R.I.P. Admiral James T. Kirk (2233-2267, 1969, 2267, 1930, 2267-2268, 1968, 2268-2269, Serpeidon Middle Ages, 2269, 2237, 2269-2286, 1986, 2286-2293, 2371)