On the Characterization of Vibrotactile Feedback in Violinists' Left Hand: A Case Study
Résumé
The long-term goal of this project is to investigate the differences in the ``feel'' of a violin that can be perceived through the left hand, across a certain range of instruments. The approach taken in this paper involves comparing amplitudes of vibration at the neck of several violins with violinists' sensitivity to vibration in their left hand. Absolute thresholds for vibration detection were measured on violinists holding an isolated vibrating violin neck, which allowed to simulate the real playing condition, in particular the pressure and the position of the hand on the neck. Using a standard alternative forced choice procedure, measurements were done as a function of frequency in the skin sensitivity range 200-900 Hz. Vibration levels of the necks were measured across a set of instruments, using a laser vibrometer and an impulse excitation at the bridge. Results show that the neck vibration levels are overall above the perceptual thresholds for most violins and at most frequencies below 900 Hz but the relative difference between the two curves can vary a lot from violin to violin. This comparison presumes the existence of vibrotactile feedback at the left hand as a potential perceived signature of the violin played.