Jain (Deemed-to-be University)’s School of Sciences organized a guest lecture on “Small Brains, Big Problems, Smart Solutions” on 12 February 2019. Dr. Rohini Balakrishnan, Chair of Centre for Ecological Sciences (Indian Institute of Science, Bengaluru) delivered a lecture. Dr. Rohini Balakrishnan is one of the leading neuroethologists in the country and is considered a pioneer in bioacoustics.
In her scientific presentation, Dr. Rohini proceeded to untangle the “Cocktail Party Problem” faced by myriad communities of insects in trying to communicate with each other amidst heavy acoustic footfall and traffic. How does a female, surrounded by such a cacophony of sounds, home in on her potential mate calling out to her? Through clever experiments, Dr. Rohini and her team have given us insightful glimpses into an alien world. Dr. Rohini’s collection of different calls made by distinct species of crickets allowed the listeners to understand how it feels to stand in the middle of a forest in the Western Ghats. She explained how the calls of different species of crickets occupy different bandwidths in the frequency spectrum. The female of each species has adapted to selectively tune-in to the frequency of the calls emanated by the males of her species while filtering out the unwanted frequencies. This allows her to locate her potential mate even in the bombardment of non-specific sounds surrounding her.
Dr. Rohini showed 3D reconstructions of the ears of crickets and explained how its position in the legs of the insect aids it in calculating the directionality of the incoming sound. Interestingly, the male crickets deceptively amplify the loudness of their calls by making holes in large leaves and using it as an amplifier. This is a strategy the males have evolved to attract females, as the latter use loudness as a proxy for the size of the male insect and tend to choose larger males for mating. An understanding of all these principles is now being applied by engineers to design robots which can analyze and respond to sounds.
Dr. Rohini ended her talk by enumerating many aspects of this field which remain a mystery till date. The session was opened to the audience for a question and answer session. Questions pertaining to the sexual dimorphism of the structure of the ear, the chemical profile of male crickets, and the possible ways by which the female can reciprocate or initiate a ‘conversation’ with the male were answered by Dr. Rohini. At the end of the session prizes were distributed to the students who participated in Science Fest – Oculus 2K19.