Whistled and drummed languages: speech carried across a valley

Speech does not travel far. A shout carries a few hundred metres at best and is unintelligible before that. In terrain where people needed to communicate across valleys or through forest, other solutions developed.

Whistled speech

Whistled languages are not codes with fixed signals. They are the local spoken language, encoded into whistling, with the whistler able to say anything they could say aloud.

They have been documented in many places, generally in mountainous or heavily vegetated terrain: the Canary Islands, parts of Turkey, Mexico, Greece, West Africa, the Amazon and elsewhere.

The whistled form carries far further than speech — reported ranges of several kilometres in good conditions — because a whistle concentrates energy in a narrow frequency band that penetrates ambient noise and travels well across open ground.

How the encoding works

It depends on the type of language.

In tonal languages, where pitch distinguishes words, the whistle reproduces the pitch contour directly. A great deal of the lexical information is carried by tone, so a whistled version preserves much of what is needed.

In non-tonal languages, the whistler encodes the vowel qualities and some consonant features by varying the pitch and the manner of the whistle. Vowels differ in their acoustic resonances, and those differences can be mapped onto whistle frequency; consonants are represented by the transitions and interruptions between them.

Either way, information is lost, and context fills the gap. Whistled conversation tends to be somewhat repetitive and formulaic, with speakers rephrasing when misunderstood, which is exactly what you would expect from a channel with reduced bandwidth.

Research using brain imaging has found that whistled speech is processed as language rather than as music, which supports the description of these systems as genuine speech surrogates.

Talking drums

The same principle applied to percussion, and it works particularly well with tonal languages.

Drums capable of producing two or more distinct pitches — most famously hourglass-shaped tension drums whose pitch can be varied by squeezing the cords — reproduce the tonal patterns of speech.

Documented extensively in West and Central Africa, and used historically for communication over considerable distances, with messages relayed between villages.

The same information-loss problem applies, and the solution is the same: standardised phrases. A short message is expanded into a longer, more redundant formula so that the tonal pattern is distinctive enough to be unambiguous. A drummer does not send the equivalent of a bare word; they send a phrase that could only be that word.

This produces a drummed register with its own poetics — a formal, elaborated version of the language used specifically for the drum.

Horns and other surrogates

Related systems use horns, flutes, xylophones and stringed instruments to encode speech in the same way.

Speech surrogates on instruments are widespread in tonal-language regions, and in several traditions instrumental music contains encoded text that speakers of the language can read, which changes what it means to listen to it.

What they were used for

Practical coordination across distance: calling people home, arranging meetings, coordinating agricultural work, warning of danger, announcing arrivals.

Also announcement and ceremony — proclaiming events, praising individuals, marking deaths, and carrying formal messages in contexts where the drummed register was the appropriate one.

And, in several documented cases, communication that authorities could not follow, which is one reason some systems were suppressed at various points.

Why they are declining

Mobile telephones, straightforwardly. A technology that allows speech across any distance at low cost removes the practical function almost entirely, and the decline in most documented whistling communities has been rapid.

Road building and the decline of the agricultural and pastoral work that required distance communication have the same effect.

Several whistled languages have been the subject of preservation efforts, including school teaching programmes, and at least one has received international heritage recognition. Whether teaching a communication system in a classroom, to children who have phones, produces a living practice is an open question, and the people running these programmes are generally realistic about it.

What is interesting about them linguistically

They demonstrate that language can be carried by channels far narrower than the full acoustic complexity of speech, and that speakers reconstruct the rest from context and redundancy.

That is a useful data point about how language works generally — the signal is always partial, and comprehension is always reconstruction. Whistled speech makes the ordinary condition unusually visible.