1. Musical Background - Pianos are extremely complicated (over 9,000 pieces) - Highly certified piano technicians can take days to prepare a concert piano using subjective judgments of sound quality. - The sound of the piano is determined by it’s tuning (pitch), regulation (key weight and responsiveness), and voicing (quality of the timbre). - The voicing is adjusted by filing, needling, and chemically treating the felt on the hammer which strikes the string as well as warping the hammer itself. - Voicing is the most painstaking part of the process, since each tweaking requires removing the action: the complex mechanism which incorporates all the hammers. - Proper voicing also sets the degree of inharmonicity. Inharmonicity refers to the tendency of the partial harmonics of a note to have slightly higher frequencies than the exact multiples of the fundamental one would expect. - The process is further complicated by the fact that no two pianos will be voiced exactly the same way. - Software exists to assist with most aspects of preparing a piano, but no such tool exists for voicing. Potential Benefits - Could cut time required to voice a piano by hours - Has use as a tool for research involving voicing - Can assist older technicians whose high frequency hearing is deteriorating - A first step towards eliminating dependence on human hearing for the voicing process Abstract In this project, we have applied Matlab’s signal processing capabilities to the creation of a set of tools to assist piano technicians with voicing. Voicing is the time consuming process of adjusting the hammers of a piano so as to achieve the most pleasing distribution of power in the harmonics of the note. Team Shank: Shannon Hughes, Andrew Swick, Darius Roberts and Douglas Duncan Methods - High precision recording of unvoiced piano notes into Matlab - Analysis of signal’s spectrum in Matlab - calculation of power in harmonics - measurement of inharmonicity - Usage of observed data to calculate action of voicing technique on the distribution of power in the harmonics - Storage of this information in a permanent reference library - Prediction of the effect of each voicing technique on a given input note - Comparison by inner products of each result with ideal spectrum (different for each piano) - Suggestion of technique on new note to attain best match with specified ideal Results - Successful analysis of signal yielding - power in each harmonic - frequency in each harmonic - inharmonicities in each harmonic - Successful creation of a reference library - Prediction of voicing techniques necessary Objective - To develop a tool to assist the piano technician with voicing which would: - Allow the technician to store information about individual pianos and voicing techniques - Assist with determining what action to take Conclusion Achieved successful design of computational tool that solves our original problem. Matlab Aided Piano Voicing Sample plot of power in harmonics Sample plot of inharmonicities Piano Hammer Mechanism