A regular listener, wondered why there were no claps of thunder following the many lightning bolts in a recent storm. The thunder actually occurred, you just couldn’t hear it. This is because light can travel much further than sound. At night, with an unobstructed view, you can see the lightning bolts from quite a distance. The sound waves associated with that lightning strike, however, can quickly dissipate. The distance that sound will travel is influenced by the atmospheric conditions, as the sound waves bounce off the molecules in the air, distorting the sound. The further the sound has to travel the greater the distortion.
Mary Knapp, Weather Data Library