Pulsatile Jet Ejected from Lips

The mechanism of sound generation by lips is studied for basic understandings of biological sound. The sound is similar to buzzing, and is known as a sound which is generated when the trumpet player blows breath to a mouth piece. The sound and vibration of lips are observed experimentally by using a microphone with a high directivity and a high-speed CCD camera. The flow through the opening of lips are observed by using a smoke visualization. The vibration of the lips model is also observed by a high-speed CCD camera with 1000 fps. The lips model shows interesting motion by jetting the compressed air. The cyclic motion of the opening and closing is observed. The frequency of motion relates the natural frequency of the model. The oscillation causes the pulsating sound that is superimposed higher frequencies. The digon shape of nozzle relates the higher frequency sound.