A big balloon filled with air explodes on the moon. Suppose we could bear the zero pressure on the ou there. Then the balloon explodes. Could we hear this explosion, from very nearby? A huge amount of air is after all released after the explosion.
Sound needs a medium. The sound of an explosion in normal atmosphere is the displacement of air , the change in pressure at the front of the explosion.
Certainly in your scenario you will not hear anything until the escaping gas reaches you. The question is whether acoustic frequency waves will exist in the air as it dissipates. My intuition is that since the explosion is outwards, there is no inner pressure wave propagating to generate acoustic waves and so just continuously rarefied air will pass you.