A Hybrid Approach to Timbral Consistency in a Virtual Instrument

The aim of this work is to make an instrument that is timbrally consistent over pitch and loudness. This particular work is not attempting to reproduce an existing instrument’s timbre, but to produce a timbrally dynamic virtual instrument that can be designed by the user. Timbre is defined by the American National Standards Institute as “that attribute of auditory sensation in terms of which a listener can judge that two sounds, similarly presented and having the same loudness and pitch, are different”. Perceptual research on timbre has identified that the main physical attributes that determine our perception of sound are the spectral distribution of energy, and its variation over time. Timbre is a time dependent attribute that evolves. It cannot have an instantaneous value. It describes an attribute of a continuous sound wave, of which an instantaneous value is just a measurement of an single relative air pressure level of the sound wave. This is all but meaningless in the context of timbre without its history or destiny. Timbre has to be analysed over time. In this paper there is a brief introduction to timbre and synthesis methods, followed by a proposal on how to make timbrally consistent virtual instruments out of given timbres.