Ancient Sounds: mixing acoustic phonetics, statistics and comparative philology to bring speech back from the pastInnovation Award
When Julius Caesar invaded Britain, declaring “veni, vidi, vici”, how did he pronounce it? Was it “weany, weedy, weaky”, as the schoolboy joke
has it? How do we know – how can we know – how Latin or other dead languages were pronounced? 19th and 20th century scholarship developed methods for reconstructing the pronunciation of words from the past, and extended this to inferring the forms of words from a time before any written records exist. For example, from word-forms as diverse as Modern English “work”, Old English “weorc”, Old High German “werc”, Latin “orgia”, Greek “ergon”, and Armenian “gorc”, philologists infer a Proto-Indo-European stem uerg-, a formula hinting at a
pronunciation something like “werg”. But what did it actually sound like?
In this project, I shall apply and further develop some new software methods developed in the last few years by me and my collaborator and project partner, the Cambridge statistics Professor John Aston, to triangulate backwards from contemporary audio recordings of simple words in modern languages to regenerate audible spoken words from the past. To achieve this we use speech signal processing techniques borrowed from speech synthesis to analyse the modern recordings, represent them using mathematical functions, infer possible and probably ancestral forms using computational statistical techniques, and finally convert the inferred ancestral forms back into audible speech, using speech synthesis. In our first experiments, we have been working on modelling sound changes that led to the current pronunciations of French, Italian, Spanish and Portuguese digits, from earlier Romance words originally going back to Latin. In this project I shall extend this work to some Germanic languages (English, German dialects and Dutch), together with Modern Greek, to try to advance the horizon of audio reconstruction into the deeper past of the Indo-European language family. This enterprise is similar to the virtual reconstruction of e.g. the visualisation through animation of dinosaurs in documentaries or films, or the reconstruction of ancient pottery or other objects. If we only have a few sherds or bone-fragments to go on, the reconstruction of a vase or skull will be largely a virtual reconstruction, e.g. a drawing or model. Audio reconstruction is, equally, a virtual addition to our construction of the past. Previously, philologists have amassed a considerable and deep understanding of what sound changes have taken place in various languages, and to some extent, when; the how or why remain areas of speculation. Acoustic modelling of speech evolution makes possible an improved understanding of what, and casts light on how, if only by unveiling possibilities. And evolutionary modelling will benefit by more refined and empirically accurate models of language change; for instance by discovering whether or how historical change in language differs in detail from biological evolution. In addition to our specific technical aims, this type of work has wider ramifications for the dividing line that is normally drawn between science and humanities. This work storms across that line, bringing science and computation into an area of work that was previously firmly part of Classics and linguistics.
Such a redrawing of disciplinary boundaries challenges and redefines old conceptions of the “two cultures” of arts vs. science. In this endeavour, each side needs the other: without the quantitative computational techniques from those sciences, comparative philologists are largely confined to written records and symbol-oriented methods; without linguistic-historical knowledge, statistical speech science would be forced to re-trace centuries of philological work, unncessarily (and perhaps unsuccessfully).