SEMI ACÚSTICO does not exist grammatically in Spanish. The rule requires writing SEMI-ACOUSTIC. What does this mean? Wind instruments are defined as acoustic bass, acoustic guitar when sounds are mostly produced independently and autonomously. When combined with electrical or electronic emitting media we have the basses and semi-acoustic guitars. On the other hand, in the case of violins we speak of acoustic and electric, because an electric violin without connecting will not emit any audible sound to the public since it requires the sound amplifier to raise the notes to an adequate volume.
