Valves
Valves are used in most types of bagpipes to close off the air entry point (the blowpipe), although some pipers simply closed the end of their blowpipe when they took a breath.
Vent Holes
On the Highland bagpipe chanter, the vent holes are two holes with produce low G; the reason for the term vent holes is unclear.
(The) Voice
An American publication dedicated to piping.