A sound effect, special effect, or design feature that is inaccurate but has become so ingrained in viewers minds that its absence would feel jarring, so creators continue to include it despite its inaccuracy.
The name of the trope comes from the sound of a horse galloping, which is created by rubbing two coconuts together. This can sound like a horse galloping, but it would only be accurate on cobblestones or other hard surfaces. On softer ground, the sound would be muffled, but in media, this sound effect can be used whenever a horse is galloping, regardless of the terrain.
1. Lion Roar (or any big cat) (Pictured: MGM logo) — The long, continuous, thunderous roar usually associated with lions is actually the roar of a tiger. For MGM, this sound began being used in the 1980s, and sound editor Mark Mangini used it because lions sounded to him more like a deep yawn or a series of grunts and lacked the kind of ferocious sound he wanted.
2. Ancient statues are always white marble (Pictured: Spartacus TV series) — Statues in ancient times were often painted in bright colors, but by the time they were uncovered, the colors had simply worn away.
3. People instantly freeze or pop like a balloon when exposed to the vacuum of space (Pictured: Mission to Mars, Total Recall) — As unfriendly as space is, a human wouldn't instantly freeze or pop like a balloon. If a person were exposed to the vacuum of space, bodily fluids would begin to boil, exposed skin would suffer severe sunburn, and they would lose consciousness after roughly 15–20 seconds. Death would occur after roughly 90 seconds.