Stemmetje (Dutch: little voice): a vocal robot created by composer and robotic musical instrument maker Troy Rogers. This singing robot consists of multiple robotically tunable Helmholtz resonators tuned to the ranges of human vocal formants.

Stemmetje is a singing vocal robot created by composer and musical robot maker Troy Rogers. It was developed at the Logos Foundation in Ghent, Belgium with Godfried-Willem Raes in 2009-10, during a residency made possible by a Fulbright Research Fellowship. The vocal robot consists of multiple robotically tunable Helmholtz resonators, the frequency ranges of which correspond to the ranges of human vocal formants.