Clue: Husband in court quietly passing wind by the sound of it (6)
Answer: WHOOSH
Explanation: Definition: passing wind by the sound of i
An envelope ('in') of H ('husband') in WOO ('court') plus SH ('quietly'; commonly in crosswords, 'quietly' indicates the musical P, while 'quiet' gives SH as an imperative, but 'quietly' can be a less strident request). In the definition, the source of the wind is, of course, atmospheric.