September 2011 Newsletter

Thursday, September 15, 2011

New Corpora

2006 NIST/USF Evaluation Resources for the VACE Program - Meeting Data Test Set Part 1

2008 NIST Speaker Recognition Evaluation Training Set Part 2

French Gigaword Third Edition


Cataloging the communication of Asian Elephants

LDC distributes a broad selection of databases, the majority of which are used for human language research and technology development. Our corpus catalog also includes the vocalizations of other animal species. We'd like to highlight the intriguing work behind one such animal communication corpus, Asian Elephant Vocalizations LDC2010S05.

Asian Elephant Vocalizations contains audio recordings of vocalizations by Asian Elephants (Elephas maximus) in Uda Walawe National Park, Sri Lanka. The data was collected by Shermin de Silva as part of her doctoral thesis at the University of Pennsylvania. Recordings were made using a Fostex field recorder with a Sennheiser 'shot-gun' microphone. In addition, de Silva utilized a second dictation microphone that allows observers to narrate what's happening without talking over the elephant recording. The digital files were then downloaded and visualized using the Praat TextGrid Editor,  a tool originally developed for studying human speech which has since been adopted by elephant researchers. With Praat, trained annotators are able to characterize call types and extract particular segments for later analysis.

Until  recently, the majority of research on the behavior of wild elephants focused on one species - the African savannah elephant. There has been comparatively less study of communication in Asian elephants, primarily because the habitat in which Asian elephants typically live makes them more difficult to study than African forest elephants. Asian and African elephants diverged from one another approximately six million years ago and  evolved separately in very distinct environments. de Silva's work has shown that Asian elephants have highly dynamic social lives that are markedly different from that of African elephants. Asian elephants tend to form smaller, fragmented groups on a day-to-day basis but maintain long-term pools of companions over many years. Because communication in elephants appears to be largely socially-motivated, differences in social behavior and ecology may also be a source of differences in their vocal behavior and repertoire.

de Silva and her colleagues study elephant communication as an opportunity to understand the evolution of social behavior and communication in a system that is very different from our own primate experience. Human language is only one manifestation of communication in the natural world. Perhaps this is why it is fitting to place animal vocalizations side-by-side with human speech in LDC's catalog. In this way, we can better understand how human language relates to the communicative capabilities of other species.

For further information on Shermin de Silva's current research at the Elephant Forest and Environment Conservation Trust visit: