Modems also make noises when connected. However, the noise of them connecting is more distinctive because they go through a handshake where you can hear distinct tones, but then negotiate a higher baud rate involving modulation of many different frequencies, at which point to the human ear it is indistinguishable from white noise (a sort of loud hissing). If you pick up the phone while the modem is connected at a higher baud rate (post the handshake), you’ll hear the hissing, and then eventually you picking up the phone will have caused too many errors for the connection to be sustained (due to introducing noise on the line), causing both ends to hang up. You’ll then hear the normal tone you hear when the called party has hung up the line.
Stargate SG-1, Season 4, Episode 6 has a variant of the loop trope, but everyone (including most of the protagonists, and everyone else on earth) don’t remember what happens, while two protagonists remember every loop until they are able to stop the looping.
They debrief the others who don’t remember at the end (except for the things they did when they took a loop off anyway!) - but they didn’t miss too much since everyone else on earth missed it.
Another fictional work - a book, not a movie / TV show / anime - is Stephen Fry’s 1996 novel Making History. The time travel aspect is questionable - he sends things back in time to stop Hitler being born, but no people travel through time. However, he remembers the past before his change, and has to deal with the consequences of having the wrong memories relative to everyone else.