2021 Volume 25 Issue 6 Pages 213-220
In this paper, we propose a real-time pitch visualization system with a “Blinky" sound-to-light conversion device. A Blinky transmits sound information as the intensity of an onboard light-emitting diode (LED). In conventional research using Blinkies, sound intensity has been converted into light intensity without utilizing spectral information. In contrast, we focus on pitch information of sound in this study and realize real-time pitch visualization as a new application of a Blinky. The proposed system consists of seven Blinkies. Each Blinky calculates a chroma vector in real time, and a pitch is visualized by activating an LED on a Blinky. We modify each Blinky for a smoother frequency response. Experimental results in a real environment show that the proposed system classifies 12 pitch classes of a musical instrumental tone reproduced by a loudspeaker with high accuracy. Furthermore, it is shown that a Specmurt-based chroma vector calculation makes it possible to suppress overtone components in a chroma vector.
