Heartbeat sounds have long been used in film, television, and online video to signal fear, excitement, love, or anticipation without dialogue, because listeners instantly recognise the rhythm of a pulse. Short versions like this one became popular for social media edits, where a creator needs an immediate emotional cue in only a few frames. The headphone note in its title reflects how the effect is meant to be felt up close, with low frequencies that are easier to notice on earphones than on phone speakers. That simplicity is why it keeps appearing in reaction clips, storytimes, and dramatic edits.