Silbo, a whistled language

Hello everyone,

        Yesterday night I saw a programme on the RTBF about Silbo, a whistled
language used by the sheperds of the Gomera (in the Canary Islands) to
to talk to others when they are at kilometers from one another (Silbo is
still understandable at more than 2 kilometers far). The programme
showed 2 scientists that were studying this language (dying because of
the appearance of new technologies) who showed that the Silbo was not an
unrelated language but a kind of whistled representation of the spoken
language. Where the spoken language had lots of harmonics, the Silbo had
only the fundamental curve of the speech plus a few harmonics, and so
could be heard farther as the energy was put only in the fundamentals.
It seems also that the Silbo originated in the tribes that were in the
Canary Islands before the conquest by the Spaniards, and which were
exterminated. But their whistled language remained and was adapted to
Spanish.

        Does anyone knows about Silbo or other whistled languages? Or about
ther kinds of languages that are meant to be heard, but are not spoken
(like Solresol, but here I'm talking about natural languages). Do you
know other whistled languages that would not be related to spoken
languages, unlike Silbo? And finally, did anyone of you make whistled
conlangs or things like that?

--
        Christophe Grandsire

        Philips Research Laboratories --  Building WB 145
        Prof. Holstlaan 4
        5656 AA Eindhoven
        The Netherlands

        Phone:  +31-40-27-45006
        E-mail: grandsir@natlab.research.philips.com