What is "rauschpfeife"

Rauschpfeife is a commonly used term for a specific type of capped conical reed musical instrument of the woodwind family, used in Europe in the 16th and 17th centuries. In common with the crumhorn and cornamuse, it is a wooden double-reed instrument with the reed enclosed in a windcap. The player blows into a slot in the top of the windcap to produce the sound. This instrument, for reasons given below, should be more correctly referred to as "Schreierpfeife."