Skype was for many years one of the most widely used calling and messaging apps on Windows, and its system alerts became familiar to anyone who sent files through it. This short error sound was the signal that a transfer had not completed, so it quickly became shorthand online for something going wrong. Editors now reuse it outside its original context, pairing it with failed uploads, glitchy software and awkward moments, because listeners instantly recognise it as an error sound even without seeing Skype on screen.