D. Kimbrough Oller, Ph.D., is Professor and Plough Chair of Excellence at the School of Audiology and Speech Language Pathology at the University of Memphis and an external faculty member of the Konrad Lorenz Institute for Evolution and Cognition Research in Austria. He was the lead author of “Automated vocal analysis of naturalistic recordings from children with autism, language delay, and typical development,” published in the July issue of the Proceedings of the National Academy of Sciences (PNAS).
In July the Proceedings of the National Academy of Sciences (PNAS) published “Automated vocal analysis of naturalistic recordings from children with autism, language delay, and typical development,” an article illustrating the rapid growth of automated technologies through efforts of the LENA Foundation and its scientific advisory board. Both the scientific world and popular press responded to the study with extraordinary interest and numerous inquiries. Over 200 publications worldwide (in at least 10 languages) have reported or commented on the article, primarily on the fact that it shows the potential for automated vocal analysis to contribute to screening and diagnosis of autism and other language-related disorders.
However, in my view the most important aspects of the article include the demonstration of the power of the automated tools to predict a typically developing child's developmental level based on a completely objective measure derived from automated analysis. What is even more notable about this proof of concept is that we designed the study to reflect empirically based theory from longitudinal research on the development of acoustic characteristics of vocalization known to be important in the emergence of speech capacity. It makes perfect sense that a method that is capable of predicting the development level of a typical child is also able to predict risk for language disorders.
These and other outcomes from working with the LENA System have taken me by surprise. When I first started studying vocal development, back in the 1970s, I did not expect to see practically useful automated vocal analysis tools for infancy and early childhood development in my lifetime. Of course, since that time we have seen the introduction of a plethora of new tools for acoustic analysis—devices a great deal more convenient and efficient than those that were available when I began my research. The development of these technologies was not such a surprise. My astonishment and delight was caused instead by the fact that my colleagues and I at the LENA Foundation were able to develop automated tools that could be applied with good reliability at massive sample sizes from naturalistic recordings in children's homes. Moreover, the very first application of our designs for automated acoustic analysis based on infant vocal development theory has proven to be very successful.
These technological developments have changed my research approach, as well as those of many researchers in my field, fundamentally. And interest in the approach is increasing. There exists a rapidly growing community of users of the LENA System and its automated labeling procedures, and these technologies are spawning a sudden and unmistakable growth of a new field of inquiry: research on speech and language conducted in natural environments with tools that are built upon the foundation of the LENA System. Young researchers have been rapidly adding to LENA System software with scripts that can be shared across laboratories to explore even more deeply the vocal systems of children recorded in their homes.
Of course, automated analysis cannot be expected to completely eclipse laboratory-based analysis of small samples of vocalizations; nevertheless, automated analysis can dramatically expand the potential for the generalizability of research and for concrete practical impacts.
It is hard to guess where things will go from here, but one thing is clear: The landscape of vocal development research has been changed as if by an earthquake. From here on researchers of vocal development and vocal interaction all over the world are going to be seeking the opportunity at every turn to incorporate automated tools and naturalistic recordings into their investigative efforts.