Sonic Cannon were weapons which fired a piercing high-pitched tone which could affect an entire block .
Block Mania Game
When the sonic cannon card is drawn, the phasing player must position the marker on any Open Air square. If all markers are in play the card has no effect. All blocker counters cost double to activate and all attacks are subject to a -1 die roll modifier.
- Block Mania (boardgame) Blockers' Manual