Imagine you are listening to the radio. Have you ever found it irritating that when they play translations of people speaking in a different language, they play a couple of seconds of the original person’s voice.
I was listening to PRI’s – The World on WLRH while driving the other day. It then struck me that the 2 second preview they play is to help the listener to differentiate between different people who might be speaking. If multiple people are voicing their comments, and there is only one translator, the only way to differentiate between them is by the preview audio sample that is played before the translation takes over.