phonogram n.

word-forming element meaning "sound, voice," from Greek phōno-, combining form of phōnē "voice, sound" of a human or animal, also "tone, voice, pronunciation, speech" (from PIE root *bha- (2) "to speak, tell, say").

noun word-forming element, "that which is written or marked," from Greek gramma "that which is drawn; a picture, a drawing; that which is written, a character, an alphabet letter, written letter, piece of writing;" in plural, "letters," also "papers, documents of any kind," also "learning," from stem of graphein "to draw or write" (see -graphy). Some words with it are from Greek compounds, others are modern formations. Alternative -gramme is a French form.

From telegram (1850s) the element was abstracted by 1959 in candygram, a proprietary name in U.S., and thereafter put to wide use as a second element in forming new commercial words, such as Gorillagram (1979), stripagram (1981), and, ultimately, Instagram (2010). The construction violates Greek grammar, as an adverb could not properly form part of a compound noun. An earlier instance was the World War II armed services slang latrinogram "latrine rumor, barracks gossip" (1944).

1835, "character representing a sound, a character used in phonography," from phono- "sound" + -graph in the sense of "something written." This older sense was rare and is obsolete.

The meaning "an instrument that produces sounds from recordings" (talking phonograph, invented by Thomas A. Edison) is attested from 1877, with -graph more in the sense of "instrument for recording." "In Britain the word is retained only for early cylinder machines, but in N. Amer. it has become synonymous with record player, record deck, etc., corresponding to British gramophone" [OED].

The recording made from it at first was called a phonogram (1879).  An earlier instrument for registering the vibrations of a sounding body was the phonautograph (1859, from French phonautographe, 1855).

You see that Edison's machine is more than a phonograph, or sound writer ; it is really a reproducer or regenerator of sound, for which a proper name would be “Palingenophone.” This is the name by which it should become known. Hitherto it has simply been called a phonograph. [Louis Elsberg, “The Throat and Its Functions,” New York: 1880]