Shellfire in the First World War - Spartacus Educational
BBC - History - World Wars: Shell Shock during World War One Mar 10, 2011 Sensuous life in the trenches - The British Library Jan 29, 2014 Gun Fire Sounds | Free Sound Effects | Gun Fire Sound
Artillery Shells in WWI : AskHistorians
Shells whistle overhead & land, debris heard settling close. Guns heard firing, distant soldiers' shouts. Two aircraft pass overhead. Smoke or gas shells heard quietly landing, then the gunfire starts up again following whistle signalling 'over the top'.
WW2 | Soundsnap
A small shell falling close to a man will have a similar effect, even if it does not explode. Thus dud-shells (i.e., those that do not explode at all) will nevertheless cause concussion. Shell Fire Sound Effects ~ Royalty Free Shell Fire Sounds