Indeed. Well they all look different but yes Homer especially sounds different for sure. For whatever reason his voice was different in the Tracy Ullman shorts and in season one of The Simpsons but season 2 is where his voice sounds like what we are used to. It has nothing to do with changing a voice actor or anything because it was still Dan castellaneta the whole time. Just for whatever reason he changed his voice much like how Lois and family Guy sounded different in season 1 even though she had the same voice actress throughout the whole series Alex borstein
Fun fact: Since they mention that Homer's voice sounds different here, in the Latin Spanish dub (I don't know about other dub) any retrospective or special appearance of the Simpsons from that time, the voice actor here also makes a very different tone of voice than usual even after having a change of actor.
Yeah, his name was Graggle Simpson. He actually appears in some of the older episodes, but the writers weren’t a fan of him, so he was unceremoniously written off.