On the subject of the internal sound. The 2014 paper on the Striso says:
The sound of the Striso is inspired by a string, where you
can both have natural decay, when plucking or hammering,
or a sustained note, with other actuation like bowing or
resonating with an amplifier
Does anyone know to what extent has this already been achieved? How feasible is it, given the current understanding of the problem, and hardware/software involved?