A stock sound effect is a prerecorded sound effect intended to be reused with an entertainment product, as opposed to creating a new and unique sound effect. It is intended to work within a sound effect library. History As far back as Ancient Greece, sound effects have been used in entertainment productions. Sound effects (also known as sound FX, SFX, or simply FX) are used to enhance theatre, radio, film, television, video games, and online media. Sound effects were originally added to productions by creating the sounds needed in real-time. Various devices and props were utilized to approximate the actual sounds, including coconut shells for horse hooves, and a sheet of metal for thunder. With the advent of radio and specifically radio dramas, the role of sound effects became more important. When cinema went from silent to "talkies", sound effects became a large part of this new medium, too. Audio recording technology continued to evolve, making it easier to record and replay sound. As this happened, the more commonly used and harder-to-replicate sound effects were pre-recorded to make them more accessible. Prerecording also allowed the same sound effect to be used many times. Both producers' and listeners' sensibilities began evolving with the technology, and the need for more realistic sound effects or for using the "real" sound increased. Therefore, a more urgent need developed for prerecorded sound effects. Over time, the quality of audio recording and playback increased, as did the demand for a wider variety of highly specific sounds. For example, rather than use a generic gunshot, a producer might request a gunshot from a specific type of gun, shot under precise conditions. Access to "real" sound effects became increasingly important to producers. These collections of prerecorded sound effects, both real and artificial, began to be referred to as stock sound effects and were organized into libraries. As their usage increased, stock sound effects libraries became the valuable assets of sound design artists and production companies. Some stock sound effects have been reused so many times that they have become easily recognizable and even cliché. Examples of these include the scream of a red-tailed hawk, castle thunder, or the Wilhelm and Howie screams. Many of the original sound effects libraries originated in the mid to late 1950s from film and television studios that employed the artists who created them, such as Warner Bros. and Hanna-Barbera. Audio Fidelity Records was