The most recent issue of Phonology (22.2) contains an article by Annie Rialland about the phonetics and phonology of a number of so-called ‘whistled languages’ (Rialland’s website has a prefinal version as a pdf).
In some sense, whistled languages use the phonology of a spoken language, such as Spanish in the case of the most well-known instance of this type of language, Silbo Gomero from one of the Canary Islands, La Gomera. Yet they implement this phonology in a radically different way — by whistling rather than moving organs in the vocal tract. Since this special type articulatory phonetics is more limited than the usual one, this in turn influences the phonology somewhat. All of this can be found in Rialland’s fascinating article.
The topic of whistled languages is also very suitable for explaining some basic principles of the phonetics-phonology interface. When I needed to write something for a Dutch popular science website for adolescents, I therefore took Rialland’s article as my basis. Spanish has a five vowel system, and Rialland shows that these vowels can be distinguished on the basis of F2 alone; it is the F2 which is whistled in Silbo Gomero. This fact can be used as a handle to explain what formants are, and what a vowel system is; here is the article I wrote (in Dutch, obviously).
I notified Rialland of the fact that I published this piece, and here is what she answered:
This paper will also serve an unexpected function for you: the Government of the Canary Islands is currently trying to get a recognition of Silbo (and also other whistled languages) as a patrimony of humanity by UNESCO. All of the papers in scientific journals (of any age) will help.
Explaining phonology to young people can have unexpected political consequences.