Why does the thunder from close lightning produce a BOOM and then a slow fade off? Why does it fade off instead of just stop? Conversely, why is thunder from far away a slow fade-on instead of an instant but quieter boom?

Question

Why does the thunder from close lightning produce a BOOM and then a slow fade off? Why does it fade off instead of just stop? Conversely, why is thunder from far away a slow fade-on instead of an instant but quieter boom?

In: 797

Answer 1

High frequency sound (the crack) is filtered more by the atmosphere across distance than the lower frequency (rumble).

See Zahorik, Brungart, & Bronkhorst, 2005 for an in-depth review of Auditory Distance Perception research