Well, actually, you couldn’t, because today I am talking about whistled languages.
They may be as rare as an honest politician, but they exist, or existed, all the same, and not just in the enchanted forests of the seven dwarfs. On the island of La Gomera in the Canary Islands, for instance, or in Turkey (Kusköy, “Village of the Birds”), France (the village of Aas in the Pyrenees), Mexico (the Mazatecs and Chinantecs of Oaxaca), South America (Pirahã), Asia (the Chepang of Nepal), and New Guinea.
It is in West Africa, though, that the sound of whistling is most common. Widely used in languages like Yoruba and Ewe, even the finest of the romance languages, French, is whistled in some places.
Whistled languages emulate the tone, prosody (rhythm/stress), intonation and vowel formants of a natural language. This then allows the trained ears of the audience to recognize the melodies and ‘translate’ them back into their natural language.
So I was wrong, in a manner of speaking one must, in fact, translate a whistled language for it to have any meaning.