"The recording of the sound of the trumpet was made in 1939 in the Egyptian Museum in Cairo for BBC radio.
The recording is so unique because since their discovery the trumpets have only been played on very few occasions. Considering their fragile state of preservation, it is very unlikely that any more attempts will ever be made again.
'Owing to its fragility, the original silver trumpet has been played only twice, in the spring of 1939, when a modern mouthpiece was inserted. At the first attempt, the trumpet was shattered but it was restored immediately and survived the eventual broadcast. The notes obtained by the military trumpeter, after the restoration, were c, e, g and c.' (From: L. Manniche, Musical Instuments from the Tomb of Tutankhamun, Oxford 1976, pp. 7-13)."