A model for real-time sound synthesis of guitar on a floating-point signal processor

Abstract

Computational modeling of musical instruments is an alternative to commonly used and more straightforward sound synthesis techniques like FM synthesis and waveform sampling. New powerful signal processors make it possible to run such models in real time. This paper deals with algorithms that can be used to synthesize guitar sounds on a floating-point signal processor. A FIR type Lagrange interpolator is introduced to implement efficient and precise fractional delay approximation that is needed to achieve arbitrary and varying length strings. This kind of interpolation is especially good in avoiding distortion and undesirable extra effects when the string length is changing continuously during the synthesis of a sound. The interpolator can also be used in other cases, e.g. in transmission-line modeling of acoustic tube resonators in wind instruments and also for vocal tract models in speech synthesis. In addition to the interpolation principle the paper describes the implementation of the guitar string model on the TMS320C30 floating-point signal processor.

Optimal fractional delay-IIR filter design using cuckoo search algorithm

“…14 shows that GA converges to a minimum magnitude error fitness value 8.3408 10 5 × − in 51 iteration cycles; Fig. 15 shows that PSO converges to a minimum magnitude error fitness value 1.5388 10 6 × − in 40 iteration cycles; whereas, Fig. 16 shows that proposed CSA converges to a minimum magnitude error fitness value 2.4512 10 7 × − in 25 iteration cycles.…”

“…Ever increasing demand of FD filters, in various applications, has revolutionized this field. These applications include time delay estimation [1], sampling rate conversion system [2], timing adjustments and interpolation in digital modems [3], speech coding and synthesis [4], modelling of the human vocal tract [5], modelling of musical instruments [6], comb filter design [7], and image interpolation [8]. Laakso et al presented an excellent tutorial on the design of fractional delay filter [9].…”

Modeling of tension modulation nonlinearity in plucked strings

“…However, it still seems reasonable to approximate the output velocity signal at position as , since the deviation term is small compared to the nominal propagation speed . In the linear case, the input signal can be fed at a single point of the digital waveguide if acceleration waves are used [26], [27]. With the nonlinear model using slope variables, the input signal is a distribution that is inserted in the two delay lines.…”

Aspects In Modeling And Real-time Synthesis Of The Acoustic Guitar

“…It was possible to implement a six string real-time synthesis model running on the TMS32OC30 signal processor (sampling frequency 22 IrHz). More details of this study are described in ref [5]. …”