It's a greater problem than just a difference in types of sensory input; it's how we perceive the sensory input once it's at our consciousness. What is it like to be another human? Let us pretend that you are cloned at birth, your clone grows up separately to you, but at no point suffers any harm to their sensory organs that you do not.
You meet one day, and go to a music concert. Your clone has been educated highly in musical knowledge, and is proficient in several instruments, whilst you, for this example, are not.
The orchestra, when tuning up, play two very close notes. You, when listening, cannot distinguish between them, but your clone can. You are both taking in the same sensory input. One of you however learns something different from hearing the two notes, whereas you do not. The key difference is how the brain responds to different sensory inputs; clearly there is something to be said for how the brain plays a part in interpretation sense data. Okay, you say. Fine, there's something to be said how you listen to something, but that's only because he's been trained in it and I haven't. If I went away and was trained as well, I would hear the same thing, cannot I simply be trained in various ways and thereby experience what it's like to be someone else?
This is where we come into identity topics again. If it is true that your brain does not contain elements of your identity or your soul (Dualism etc), then you are allowed to claim that you could experience what it is like to be in his brain without altering you. If it is not true, and your brain does contain who you are, it is seemingly impossible for you to remain you, whilst also experiencing what it is like to be him.
When you wish to experience what it is like to be a bat, how may you have the intelligence of a bat whilst also still being yourself? | This may be another reductive attempt to understand a subjective phenomenon, but it seems plausible to me that my red is the same (or similar) to most other humans perception of red simply because, give or take a few cone and rod cells, a human eye is a human eye.| A completely reasonable interpretation, and entirely what most people will accept so that they can carry on with life. As with a lot of these problems, it's not just the answer that matters, but how we get to the answer.
Colour is the same amongst all humans? Well that shows a clear sign that the world is physicalist; nothing that is not physical exists. If it isn't we suddenly have to explain what causes a difference in colour perceptions between humans.
The explanatory gap is huge because of how particles of energy give rise to such vivid experiences in our minds; we can't really seem to grasp why a packet of light particles suddenly makes us overcome with the experience of "Red". Also I know I've posted long criticisms on TheAdvancedApes twice now, but I do really like your work, that's why I'm happy to put the effort into providing another side!Since bats actually utilize a form of perception alien to a human, perhaps that explains why it is we can’t really know what it’s like to be a bat.