Loudest possible sustained sound in air

As sound is a wave, the loudness of any sound relates to the amplitude of that wave – ie, how high and low the peaks and troughs of the wave are. The peaks and troughs of a sound wave oscillate around the average of 1 atmospheric pressure. The lowest possible troughs of a wave are at 0 atmospheres, or a pressure of zero. The highest troughs of such a wave would show symmetry and be at 2 atmospheres. A sound wave with amplitude range of 2 atmospheres corresponds to 194 dB. Any event louder than 194 dB is considered a shock wave.