The eolh iarr'voi was a palm-sized Romulan instrument played by inhaling and exhaling along a narrow reed.
In 2157, an eolh iarr'voi was in the possession of Trip Tucker. Tucker played it when he was aboard the ChR Ra'kholh and Terix destroyed the instrument. Tucker was disappointed because he said it was the closest he had come to getting a harmonica in a long time. (ENT - The Romulan War novel: To Brave the Storm)