Integration of user perceptions in the design process: Application to musical instrument optimization

This paper describes a user-centered design method, which allows the integration of user's perceptions in different stages of the design process, by taking into account his/her needs and preferences. It relies on two domains which remain generally distinct: the design with a scientific approach (generally math based) and the integration of users perceptions, preferences, tastes, inherently subjective. We apply this method to the design of musical instruments, products for which the feelings of the user are of prime importance, and remain so far difficult to integrate for the design/improvement of an instrument. The methodology is made of two main stages: (1) a subjective study, based on the sensory analysis techniques, during which a "product space" (a family of trumpets) is assessed by a panel of experts according to sensory attributes, and (2) an objective study Of the instruments, based on the physical measurement of a specific characteristic of brasses: the acoustic input impedance. Then, data analysis is used to correlate perceptive and objective evaluations, in order to deduce design rules and to formulate the improvement of a perceptive characteristic of the product (the intonation) as a multicriteria optimization problem. The design of the inner shape (the bore) of a "new " instrument is finally made by solving the multicriteria optimization problem using genetic algorithms.