A sound hole is an opening in the body of a stringed musical instrument, usually the upper sound board. Sound holes have different shapes:
The sound holes of cellos and other instruments of the violin family are known as F-holes and are located on opposing sides of the bridge.
Leaf sound hole in an Ovation Adamas guitar
Many acoustic guitars incorporate rosette patterns around the sound hole.
Maccaferri guitars have D or oval shaped sound holes.
An archtop guitar is a hollow acoustic or semi-acoustic guitar with a full body and a distinctive arched top, whose sound is particularly popular with jazz, blues, and rockabilly players.
Sound hole
…Round in flat-top guitars and traditional bowl-back mandolins; F-holes in instruments from the violin family, archtop mandolins and in archtop guitars; C-holes in viola da gambas and occasionally double-basses and guitars…
G6122-1962 Gretsch Chet Atkins Country Gentleman developed in the mid-1950s
The Epiphone Dot, an inexpensive thinline archtop available since the 1990s