Why do Miao, Yi and Wa people hollow out the inside of wooden drums when making them?

In order to form a cavity, the sound is amplified.

Almost all acoustic instruments have a cavity, and sound waves collide with each other repeatedly in the cavity, amplifying the sound of the instrument before being heard.

Because the origin of all musical instruments faces this problem, that is, amplification. For example, plucked instruments originated from hunting bows. It is found that different bows can make different tones, but the sound is too small to be used for playing. Later, people installed hollow wooden boxes, and now there are acoustic guitars, winter blues, banjo and so on. The origin of drums is that people put skins on hollow rotten wood to dry, and when they are dry, they can make a loud sound.

Therefore, it is necessary for acoustic instruments to have * * * speakers, especially drums.