Acoustic guitar plucking point estimation in real time

The algorithm estimates the plucking point of guitar tones obtained with an undersaddle pickup. This problem is approached in the time domain by applying autocorrelation estimation. This work extends a recently developed algorithm and brings it to a practical and sufficiently robust level. Improvements have been made to the onset detection part of the algorithm. The algorithm also enables a new way to control, for example, audio effect parameters in real time by simply changing the plucking point. The paper discusses these issues and the real-time implementation in the Pd environment. In tests, the real-time implementation achieved a 96% hit rate while the estimation error remains smaller than one centimeter, except for a few outliers. Audio samples and a Pd implementation of the algorithm are available on-line at www.acoustics.hut.fi/demos/plucking-point/.