Bivariate Mixup for 2D Contact Point Localization with Piezoelectric Microphone Array

Aiming at capturing interactions between a human hand and a desk when seated at a desk, we address the task of localizing the position of a hand touching a desk from the contact sound.Our framework uses an array of contact microphones called piezoelectric devices mounted on the desk to regress the 2D coordinates of the hand position from the resulting contact sound.Training a qualified regression model requires a number of high-quality training samples, but collecting accurate ground truth coordinates is often costly.To address this problem, we propose a novel data augmentation technique customized to 2D regression problems named Bivariate Mixup (BiMixup).BiMixup is a generalization of Mixup, which is formulated as a univariate linear interpolation, to a bivariate quadratic interpolation.Experimental results using a real sound dataset show that our BiMixup reduces the error by 12.2 % compared to the original Mixup.