This is what a dial up modem connection looks like on the spectrogram (DTMF handshake and call). : r/interestingasfuck
Stream Modem Us Robotics 56k Sound by EmanuelFRSP | Listen online for free on SoundCloud
56k modem internet connection sound - YouTube
Dial Up Modem Sound Effects - 21 Dial Up Modem sounds for SFX projects | Pond5
A Nostalgic Compilation of Dial-Up Modem Sounds
The Mechanics and Meaning of That Ol' Dial-Up Modem Sound - The Atlantic
Dial Up Modem Sounds, 56K Edition - YouTube
Freesound - "56k Modem.mp3" by BlueNeon
Der 56k Modem Klang - The 56k dialup modem sound - YouTube
RetroTech Chris on Twitter: "Testing out my "new" US Robotics 56K Faxmodem. Dialed up the Diamond Mine BBS. Sound on if you like modem sounds. https://t.co/4yoKUNi1ji" / Twitter