I was chatting to my son about the British really popular Police drama Line of Duty. I was interested as he's a Police Officer here. I expected him to moan about Police process mistakes, or the things they do, but no - his complaint was the interview recorders which are the latest type - solid state and  when you hit the button they make the long loud tone, before they start recording. He says they don't do this - just a pip or two to indicate they have started. He pointed out the long beep was the old dual cassette machines which had a loud tone to prevent you trying to record on the leader. The TV programme dub  on the traditional long tone because everyone has got used to hearing this in Police dramas. Ironically, if he has to interview anyone in the local Police Station they still use Cassettes! Loads of them. Only the larger custody suites in our Police Service have the new clever machines! I figured they're long dead - but cassettes still live as current recording media here!