The carnyx was a metal wind instrument used by Celtic peoples around two thousand years ago. It was approximately two meters long with a bell in the shape of an animal head. In 2004, an excavation at Tintignac in the Corrèze district of France uncovered a horde of bronze instruments, including parts of several carnyxes. It proved possible to assemble an almost complete carnyx from these parts, and in 2011, a copy of this carnyx was made in brass by Jean Boisserie. The acoustical behavior of the brass copy was studied by Joel Gilbert and colleagues at the Université du Maine in Le Mans; this work led to the proposal that the musical performance of the instrument would be improved if an additional section of tubing was included in the reconstruction. Later, Boisserie made a second copy in bronze, together with several optional extension pieces. The musical performing possibilities of the bronze copy have been studied by the musician John Kenny, and its acoustical behavior has been studied at the University of Edinburgh. The results of these studies, including measurements of sound radiation by the large bronze ears attached to the head, are presented and discussed.