ACOUSTIC a.
auditory 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.
PHONOGRAPH n.
An instrument for the mechanical registration and reproduction of audible sounds, as articulate speech, etc. It consists of a rotating cylinder or disk covered with some material easily indented, as tinfoil, wax, paraffin, etc., above which is a thin plate carrying a stylus. As the plate vibrates under the influence of…