PRISMA: A 'Timbre Tuning Device' for Musicians and Instrument Makers

PRISMA is a measuring system for the analysis of musical instrument sounds. It works either in real-time or with given wav-files. It computes selected features of a sound and displays them numerically or graphically. The user can choose the features and adjust content and scaling of the diagrams as well. Finally, the results can be printed and stored. The hardware is designed portable and consists of a microphone, a sound card and a laptop computer. Thus it can easily be taken to the workshop of an instrument maker, a school or a concert hall. The sound analysis is based on a short time Fourier transform and a high precision fundamental frequency estimator. The latter is a novel combination of frequency and time domain methods. Instead of applying an explicit partial tracking process we use an intuitive classification of peaks in the local spectra. The PRISMA software was written in C++ and runs unter Windows XP. Newer versions of Windows are not tested but work at least on some computers. The practical use of the system is multi-functional. It may serve as a high resolution measurement tool for instrument makers a visual aid for instrument players and teachers a way to find better expressions for the description of timbre - a measurement device for musical acoustics research