 The pulsation is the most important component to the oscillation, acoustically, because by changing the gas volume, it changes its pressure, and leads to the emission of sound at the bubble's natural frequency.For air bubbles in water, large bubbles (negligible surface tension and thermal conductivity) undergo adiabatic pulsations, which means that no heat is transferred either from the liquid to the gas or vice versa.The natural frequency of such bubbles is determined by the equation