WIND SIGNAL n.
In general, any signal announcing information concerning winds, and esp. the expected approach of winds whose direction and force are dangerous to shipping, etc. The wind-signal system of the United States Weather Bureau consists of storm, information, hurricane, hot wind, and inland storm signals.
ACOUSTIC a.
duct, or external passage of the ear. -- Acoustic telegraph, a telegraph making audible signals; a telephone. -- Acoustic vessels, brazen tubes or vessels, shaped like a bell, used in ancient theaters to propel the voices of the actors, so as to render them audible to a great distance.