At DFC, communication is both our business and our obsession. We strive for the perfect balance of simplicity and effectiveness in each solution we provide. That’s why I am bowled over with admiration for a unique method of inter-village communication devised by the Bora people of the Peruvian, Brazilian, and Colombian Amazon. Recently studied for the first time in depth by linguist Frank Seifart of the University of Cologne, the Bora “public address” system uses drumbeats to send messages across large distances. But instead of requiring a separate code or language, drummers and their drums represent the tones and timing of spoken Bora — resulting in messages that are easily understood by community members kilometres away.
This style of communication has been common for centuries among cultures with tonal languages, including Yoruba, and Chin. Bora has two tones, low (coded as female) and high (coded as male) — so two drums made of hollowed tree trunks (called manguaré) are required.
Seifart and team undertook their study in collaboration with five drummers and drums in the Bora region, and collected a staggering amount of specific data that had been handed down traditionally for generations.
“As predicted, the tones of the 169 drummed messages matched the high and low tones of spoken Bora. Words appeared in a formulaic order, and nouns and verbs were always followed by a special marker. […]
When the team compared the drumbeats to the words they represented, they found a second pattern: The intervals between beats changed in length depending on the sounds that followed each vowel. If a sound segment consisted of just one vowel, the time after the beat was quite short. But if that vowel was followed by a consonant, the time after the beat went up an average of 80 milliseconds. Two vowels followed by a consonant added another 40 milliseconds. And a vowel followed by two consonants added a final 30 milliseconds.”
This slight difference in rhythm makes completely different drummed messages (“go fishing” vs. “bring firewood”) thoroughly intelligible — and may, Seifart and co. theorize, be transferable to spoken, non-tonal languages too. Linguistics experts have long been stumped by the “cocktail party problem”, lacking an explanation for how the human brain can make sense of words spoken in noisy contexts (like a conversation with a friend in a loud bar). The human awareness of small changes in rhythm, even if unconscious, may point to a fascinating new direction for research!