What does Resonator mean?
Trapped air volume in a container (which upon excitation makes
a sound; for example, blowing across a bottle mouth). This
forms a resonator. The air in the cavity is like a coiled
spring and the mass of the air in the neck of the bottle
reacts with this property to form a resonating system. The
sound so produced has a frequency characteristic of the air
volume, diameter of the mouth and length of the neck of the
resonator. Change any one of these, and the frequency of the
emitted sound changes.