Hi Milum,
A thunderclap produces a similar "Bang" as air rushes in to fill the vacuum left by a lightning strike..
Unfortunately this is an old erroneous myth. The lightning strike does not leave a vacuum. It simply heats up the air incredibly quickly, and the resulting expansion makes itself felt as a bang. The crackling sparks of static created when you pull off your acrylic sweater, are miniature models of the phenomenon.