User:JerroldOng/sandbox

Function
The Silbo Gomero language is generally used in circumstances of public communication. Due to the loud whistling nature of Silbo Gomero, users of the language expect other users to be able to hear and understand the utterance being conveyed. Messages conveyed could range from being an event invitation or even public information advisories.

Manuel Carreiras of the University of La Laguna and David Corina of the University of Washington published research on Silbo in 2004 and 2005 arguing that Silbo was understood by the brain in much the same way as a spoken language. Their study which comprised of speakers of Spanish, had participants of whom "spoke" Silbo and of some of whom did not. By monitoring the brain activity of their participants with functional magnetic resonance imaging, results show that while non-speakers of Silbo merely processed Silbo as whistling, speakers of Silbo processed the whistling sounds in the same linguistic centers of the brain that processed Spanish sentences.

Features
The Silbo Gomero Language has only only 2 vowels and 4 consonants, according to the official nomination document submitted during the UNESCO convention. As with other whistled forms of non-tonal languages, the Silbo works by retaining approximately the articulation of ordinary speech, so "the timbre variations of speech appear in the guise of pitch variations" (Busnel and Classe: v). The language is a whistled form of a dialect of Spanish. Silbo replaces each vowel or consonant with a whistling sound. Whistles are distinguished according to pitch and continuity.

Vowels
The vowels of Silbo Gomero are described roughly as sustained lines of high and low frequency that are distinct from each other. The high frequency /i/ vowel represents the vowels of the spoken language being whistled, while the low frequency whistle of the dark /a/ vowel represents the vowels. It is said that it is not possible to produce any vowels with intermediary frequencies as the whistling mechanism does not have the same functions that the vocal mechanism possess. The theory that Silbo Gomero has only two vowels was theorised by Ramón Trujillo of the University of La Laguna in his published book "EL SILBO GOMERO análisis lingüístico" in 1978. His work, containing almost a hundred spectrograms, concludes in a theory that there are only two vowels and four consonants in the Silbo Gomero language. In Trujillo's work Silbo's vowels are given one quality, that of pitch, being either high or low. However, in a more recent study, the work of Julien Meyer (2005 - in French only (pg 100), 2008) gives a statistical analysis of the vowels of Silbo showing that there are 4 vowels statistically distinguished in production and that they are also perceived so. Also in 2005, Annie Rialland of the University of Paris III: Sorbonne Nouvelle published an acoustic and phonological analysis of Silbo based on new materials, showing that not only gliding tones but also intensity modulation plays a role in distinguishing different whistled sounds.

Trujillo's 2005 collaboration with Gomeran whistler Isidro Ortiz and others ("EL SILBO GOMERO Materiales didácticos" - q.v. pdf link below) revises his earlier assertions to state that 4 vowels are indeed perceived (q.v. pg 63 ref. cit.), and describes in detail the areas of divergence between his empirical data and Classe’s phonetic hypotheses. Despite Trujillo's 2005 work acknowledging the existence of 4 vowels, his 2006 bilingual work ("El Silbo Gomero. Nuevo estudio fonológico") inexplicably reiterates his 1978 two-vowel theory. Trujillo's 2006 work directly addresses many of Rialland's conclusions, but it seems that at the time of that writing he was unaware of Meyer's work.

Meyer suggests that there are 4 vowel classes of, , ,. However Meyer goes on to say that there are 5 perceived vowels with significant overlap. Rialland (2005) and Trujillo (1978) both agree that the harmonic of the whistle matches the second formant of the spoken vowels. Spoken 's F2 and whistled 's H1 match in their frequency (1480 Hz). However there is a disconnect in harmonics and formants near the frequency basement. Spoken speech has a wide range of F2 frequencies (790 Hz to 2300 Hz), whistles are limited to 1200 Hz to 2400 Hz. Vowels are therefore shifted upwards at the lower end (maintaining 1480 Hz as ) increasing confusion between (spoken F2  freq 890 Hz, whistled <1300 Hz) and  (spoken freq 790 Hz, Whistled <<1300 Hz). In whistling the frequency basement must be raised to the minimum whistle harmonic of 1000 Hz reducing frequency spacing in the vowels, which increases misidentification in the lower vowels.

Consonants
Consonants in Silbo Gomero are modifications of the vowel-based “melody line” or “vocal line”. They may be rising or falling or can also be modified by being broken, continuous or occlusive. The four main consonants are as follows :

The documentation on the official Silbo Gomero page on the UNESCO websiteis in line with Trujillo’s 1978 study. Trujillo (1978) suggested that the consonants are either rises or dips in the "melody line" which can be broken or continuous. Further investigation by Meyer, and by Rialland suggest that vowels are stripped to their inherent class of sound which is communicated in the whistle in these ways: voice ( vs ) is transmitted by the whistled feature -continuity. A silent pause in the whistle communicates +voice, while a +continuous consonant gives the quality -voice. Placement of the consonant (dental, palatal, fricative) is transmitted in whistle by the loci of the formant transitions between vowels. Consonant classes are simplified into four classes. Extra high loci (near vertical formant loci) denotes affricates and stridents, rising loci denotes alveolar, medial (loci just above the vowel formant) denotes palatal, and falling (low loci) denotes pharyngeal, labial, and fricative. This gives 8 whistled consonants, but including tone gradual decay (with intensity falling off) as a feature on continuous and interrupted sounds gives 10 consonants. In these situations gradual decay is given +voice, and continuous is given +liquid.