Thunner is the soond caused bi lichtnin. Dependin on the distance an naitur o the lichtnin, thunner can range frae a sharp, loud crack tae a lang, law rumble (brontide). The sudden increase in pressur an temperatur frae lichtnin produces rapid expansion o the air surroondin an within a bolt o lichtnin. In turn, this expansion o air creates a sonic shock wave, seemilar to a sonic boom, which produces the soond o thunner, eften referred tae as a clap, crack, or peal o thunner.