Generalized modeling of body response of acoustic guitar for all frets using a response for single fret
Publication date: February 2019
Source: Applied Acoustics, Volume 145
Author(s): Minakshi Pradeep Atre, Shaila D. Apte
Analysis of music notes with their mathematical behavior has been the topic of interest since ages. This work is focused on the analysis of acoustic guitar notes to calculate and rather separate the guitar body response or impulse response and the excitation signal. The cepstral domain approach is used for estimation of guitar body response. The adaptive cepstral domain windowing (ACDW) is adopted to estimate the guitar body response. The guitar notes for two plucking styles, finger plucking, and plectrum plucking were recorded for all the twenty frets. This resulted in the database of two hundred and forty sound notes including both plucking styles. The complete analysis of the behavior of the guitar body on the coarse level, that is, string level and on fine level, that is, individual fret level, is carried out. This paper discusses the extraction of impulse response of acoustic guitar for all strings and all frets. This present work is extended to put forth a generalized mathematical model for the impulse response of acoustic guitar for all frets using a response for a single fret as a base. It discusses the formulation of a mathematical equation for finding the body response of one fret using the body response of the last fret. The body response so obtained is convolved with the excitation for the required fret using mathematical equation. The result is verified with the subjective listening test by the experts and with the objective measure as the correlation coefficient, the statistical parameter to indicate the degree of matching. It is observed that the synthesized fret note shows the correlation of more than 0.84 with the actual fret note. The listening tests results by the experts also give a score of more than 0.9 for the synthesized notes.