Exploring and interpreting the spectral structure of the North Indian flute (Bansuri)

Spectrograms are powerful tools in many fields today, whether that be by a musician trying to improve their own ability with an instrument or an engineer developing a way to sense vehicles for an autonomous car. The spectrogram allows for deeper analysis than just what can be heard, giving information on its harmonic series, any frequencies below 20 Hz or above 20 kHz (range of hearing) and beyond. In this talk, we will explore the efficacy of spectral analysis to understand the acoustical structure the Indian flute (Bansuri) and provide interpretation of the melodic sounds generated by this ancient Indian instrument using spectral analysis. Specifically, we examine what harmonic features characterize the fluid melodic movements of the Bansuri and whether non-harmonic structures in the acoustic spectrogram carry pertinent musical information. We also qualitatively examine the accuracy of extracting the melodic features against non-melodic features that sound like dissonant hiss. We will discuss the potential of understanding the air column physics of this flute and relating it spectrally to similar physics of propagation in small cylindrical underwater sonar targets such as unexploded ordinances (UXO). Results based on original flute data (and potentially UXO and similar small-target sonar data) will be presented. [This work has been partially supported by the DoD Navy grant N00174-20-1-0016 and University of Iowa internal funds.]