A connection on an audio or audio/video component which receives a headphone connection. The headphone jack allows a person so listen to program material through headphones instead of through traditional speakers. In this way, someone can enjoy audio any time of the day or night without risk of bothering others in the area. The headphone jack is a small, round hole into which the headphone plug is inserted. Headphone jacks come in two common sizes, the quarter inch phono plug and eighth inch headphone plug.