No, I'm claiming that it's safe for me to assume that I can see much the same stuff as anyone else with eyes can, or hear much the same kinds of sounds, since I appear to have the same kinds of eyes and ears. I have never said that everyone shares my perceptions - this implies that I'm somehow "sharing" my experiences of seeing and hearing with others. This can't be possible, since everyone has their own eyes and ears, their own distinct brain which is separate from mine...? I assume that the experience of seeing is universal for people with functional vision, and that it must be a lot like, or the same as my experience, since the equipment is the same. I have nothing but my experience and the way I compare that with what I believe others experience, which I can never know except through intuition. But this is how we function, how any group of social animals functions - by assuming common experience. We wouldn't do so well at coordinating activities the way we do, if we did not assume this common ground (of experience, of how we see and hear the world and each other). Would we now?