-ˌfōn noun
Etymology: piston + -phone
: an instrument for measuring acoustic intensity by the displacement of a piston resulting from the sound pressure upon it
-ˌfōn noun
Etymology: piston + -phone
: an instrument for measuring acoustic intensity by the displacement of a piston resulting from the sound pressure upon it
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012