What is the range of a trumpet

Bauhaus University Weimar Works with a filter: brass music in Corona times

Wind instruments emit much less air than expected

A streak mirror can be used to make air currents visible. These appear like cloudy and moving streaks on the mirror surface. As far as the air expulsion goes, the streaks reach into the mirror.

"It finally came out that none of the instruments pushed more than 1.1 or 1.2 meters of air into the room," says Becher. Originally it was assumed that the air from the instruments would reach twelve meters into the room, but there were errors in the conversion, says the physicist. "And then later it was still three or four meters that should be kept between the brass musicians. That has then been reduced more and more, probably thanks to our merit, because we were able to show that the output is much lower than originally assumed. "

Filter is effective on brass players

Lia Becher cannot say whether and how many viruses the expelled air contains. The experiments only show the air circulation. But it was possible to demonstrate how effective the simple cellulose filter is. Through its use, the range of the breathing air that is drawn into the room when playing the instruments could be greatly reduced. This worked particularly well with the flute: the blown air could be reduced from one meter to less than 15 centimeters. And that, the building physicist assures, without the sound suffering significantly.

Of course, it should also be noted that the air output in the instrument ultimately has nothing to do with the sound. So the sound simply needs a medium, the air in this case so that it can be transported. But that also works without the air expulsion.

Lia Becher, Bauhaus University Weimar

The flute is also the only woodwind instrument that can be fitted with a filter because a large part of the air is blown through the mouthpiece. For the others, most of the air comes out of the clay holes. In contrast to brass instruments, says Lia Becher, because here all of the air you breathe escapes from the bell.

Sound quality in bands should be checked at concerts

Further experiments will show whether the sound is stable even in large groups. Andreas M├╝hlenberend is currently in the process of setting up a brass band made up of Weimar musicians, which will be equipped with filters. At a concert, the sound quality should be assessed more precisely.