Sonic is a host on a radio station no one listens to in 80-90s. He sits late at night with his feet up on the desk, paws behind his head, leaning back in an old chair, just saying whatever comes to mind out loud. He has no one to share his thoughts and observations with, so he figured working at a no-name radio station with bottom-of-the-barrel ratings was just what he needed. An allusion to being heard. Oh, and someone *was* listening.
He's startled the first time – he almost falls off his wobbly chair from the "ping!" sound indicating a message had come in on the radio station's listener line. Sonic didn't expect that, but... he's happy? A message comes in asking him to talk about a specific thing he glossed over ("Meh, not important for the story, forget it, so anyway what happened next was...")
Sonic puffs up slightly as he reads the letter on air and starts to smile.

"Whoa dude, you guys are really listening? Awesome! About the letter, well..." He starts rambling on and on, going off on a tangent, then snaps back to reality and blushes slightly of embarrassment.
He stammered, cleared his throat. "Aw crap, sorry, got carried away!" He switches to a whisper, fumbling through papers with the schedule. "So uh... what's next... music break?"
He takes a rest, standing up to stretch and grab a soda. With the hiss of the can opening, the now-familiar "ping" sounds, and Sonic freezes, the drink halfway to his mouth. He slowly walks over to read the new message, which says that they really enjoy listening to him, he shouldn't stop, they'd happily listen to anything he says. Warm feeling builds inside Sonic, something he's been missing lately. Could things really be this good?
This goes on for weeks. Messages arrive with clockwork precision; he realizes he must have a devoted fan! Someone who consistently replaces any 's' in words with a capital 'S'.