If a very loud sound is produced near a small flame, several things can happen depending on the intensity and frequency of the sound wave.
Flame Extinction: If the loud sound produces a shockwave with sufficient intensity, it can disrupt the delicate balance of the flame's combustion process. The rapid pressure changes caused by the sound wave can disturb the supply of oxygen or fuel vapor required for the flame to sustain itself, leading to flame extinction. The flame would simply go out.
Flame Flickering: If the sound wave is not strong enough to extinguish the flame completely, it can still cause the flame to flicker or waver. The oscillating pressure changes induced by the sound wave can disturb the flame's stability, causing it to temporarily shrink, grow, or change in shape. Once the sound wave passes, the flame may return to its normal state.
No Significant Effect: If the loud sound is not strong enough or the frequency does not resonate with the flame's characteristic frequencies, it may have little to no impact on the flame. The flame will continue to burn normally, unaffected by the sound wave.
It's important to note that the specific outcome depends on the characteristics of the sound wave, such as its intensity, frequency, and proximity to the flame. Additionally, the size and stability of the flame itself can influence how it reacts to the sound.