For me, it's also the sound of modems, here's a small story explaining my personal connection to these modem sounds. In the 90s I used to get my emails from BB

For me, it's also the sound of modems, here's a small story explaining my personal connection to these modem sounds. In the 90s I used to get my emails from BBSs and frequently the first thing I did after waking up was to boot up the PC and make it call the (at those times usually busy) BBS. While taking a shower, brushing teeth, getting dressed etc... there was this long chain of Pick-up, Dialtone, Dialing, Busy... Wait. Pickup, DIaltone, Dialing, Busy... Wait. Pickup, Dialtone, Dialing, Busy... until finally, maybe after 10-15 minutes it would connect, so I could sit down on the computer and check for new emails. Then there was the 2nd call to upload replies to the BBS... This was daily routine for a few years! I still own the trusty Telebit T2500 and a USR Courier, I think I'll have to put them up my small Server/NAS just for the fun of being able to dial in and fetch my emails, maybe with an android-phone? ;-)