Generally, musical instruments have a whistle. The place where the ball is placed in the whistle is the whistle. All vibrations will make sounds, but the sounds can be loud or small. With a whistle The sound of the whistle will be enlarged many times.

The sound of the whistle is due to vibration, but the loud sound is the whistle, which is caused by the vibration. The frequency of the whistle is determined by many factors. It is very sensitive. Blocking it with your hand will change the frequency of the sound box and stop it from sounding.

The pellet in the whistle is not necessary, and many whistles do not have it.

< p> When we play the flute, the gas enters the inside of the flute from the edge of the blowing hole and makes a vortex motion at the blowing hole. This reduces the gas pressure inside the blowing hole, so the gas at the tail of the flute moves toward the blowing hole (this speed Quickly, imagine the air as a very elastic thing, which is actually the case). The sound is accumulated at the blow hole. This movement causes the pressure at the blow hole to increase, but the mouth wind continues to blow ( Physically called excitation), the gas is pushed to the tail of the flute, and then the pressure at the blow hole decreases again, and the gas moves toward the blow hole again. In this cycle, the vibration produces sound.