A landmark article on nonlinear time-domain modeling in musical acoustics.

The Reflections series takes a look back on historical articles from The Journal of the Acoustical Society of America that have had a significant impact on the science and practice of acoustics.

Electric-to-acoustic pickup processing for string instruments: An experimental study of the guitar with a hexaphonic pickup.

A signal processing method to impart the response of an acoustic string instrument to an electric instrument that includes frequency-dependent string decay alterations is proposed. This type of processing is relevant when trying to make a less resonant instrument, such as an electric guitar, sound similar to a more resonant instrument, such as acoustic guitar. Unlike previous methods which typically only perform equalization, our method includes detailed physics-based string damping changes by using a time-varying filter which adds frequency-dependent exponential damping.

State-space modeling of sound source directivity: An experimental study of the violin and the clarinet.

A method is presented for simulating the free-field, frequency-dependent directivity of linear sound sources for use in real-time within geometric acoustic environments. The method, which is applied to modeling the directivity of a violin body and a clarinet air column from experimental acoustic data in this study, is based on using minimum-phase measurements to design a state-space filter, allowing the interactive simulation of a time-varying number of radiated sound wavefronts, each toward a time-varying direction. With applicability in sound synthesis and/or auralization within virtual environments, where sound sources change position and orientation dynamically, techniques are proposed for modeling and simulating directivity profiles on perceptual frequency axes with alternatives for representing directivity on a per-vibration-mode basis while incorporating relative phase terms or by reduced-order efficient representations comprising separate components for the signature resonant structure and the associated directivity on an adjustable frequency resolution.

Modeling sound scattering using a combination of the edge source integral equation and the boundary element method.

A hybrid method for sound scattering calculations is presented in this paper. The boundary element method (BEM) is combined with a recently developed edge source integral equation (ESIE) [J. Acoust.

Feedback control of acoustic musical instruments: collocated control using physical analogs.

Traditionally, the average professional musician has owned numerous acoustic musical instruments, many of them having distinctive acoustic qualities. However, a modern musician could prefer to have a single musical instrument whose acoustics are programmable by feedback control, where acoustic variables are estimated from sensor measurements in real time and then fed back in order to influence the controlled variables. In this paper, theory is presented that describes stable feedback control of an acoustic musical instrument.

The simulation of piano string vibration: from physical models to finite difference schemes and digital waveguides.

A model of transverse piano string vibration, second order in time, which models frequency-dependent loss and dispersion effects is presented here. This model has many desirable properties, in particular that it can be written as a well-posed initial-boundary value problem (permitting stable finite difference schemes) and that it may be directly related to a digital waveguide model, a digital filter-based algorithm which can be used for musical sound synthesis. Techniques for the extraction of model parameters from experimental data over the full range of the grand piano are discussed, as is the link between the model parameters and the filter responses in a digital waveguide.