Apparently the two trumpets, one made of bronze, one of silver, were played for a radio broadcast in 1939. True to the spirit of the curse of Tut’s tomb, all kinds of things happened around them. The day of the broadcast the lights at the museum failed an hour before the broadcast. Supposedly every time they have been played, a major international incident has taken place.
This article in the BBC News details the performance and includes a sound clip of the sound of the trumpets. They didn’t play very well in tune, and it sounded as if they were very hard to control. Of course, they are really what we would call bugles today, since they lacked valves.
In the Baroque and Classical periods, before the use of valved trumpets in the orchestra, “natural” trumpets very much like these were used throughout Europe. Trumpet players became members of guilds and apprenticed to learn to play using the higher overtones of the instrument, where more diatonic notes are available. Such playing is very demanding on the facial muscles. Since we have absolutely no idea what kind of music was played on them, we don’t know if they had to have great high chops like the clarino trumpet players of the Baroque.
Of course, maybe this was the music of the time: