I enjoy loud music & bright lights & some hustle & bustle about me, provided I am not expected to participate much. Being able to sit back a bit & observe helps a lot in managing response to strong stimuli.
Due to mild seasonal allergies, I have a poor sense of smell & am not bothered by scents at all. I can also block a lot out when it comes to details... I miss many physical details easily, and some of it is out of necessity (block out or get overwhelmed, I guess). This gives me that characteristic INFP "dreamy" appearance where I float past things & don't see them.
However, strong atmospheric tones can affect me a lot. This will sound silly, but a very ugly environment will greatly affect my mood. If something is aesthetically "off" then it can aggravate me, but not like crooked pictures or anything like that; I mean more of an overall mood. I'm way more "vibey", processing things semi-unconciously, not alert to specifics, but I'm very affected by them nonetheless. It's hard to know what is bothering me sometimes, because I cannot always pinpoint something. I think it's more of an emotional sensitivity than a physical sensitivity to sensory stimuli.
I also get overwhelmed in certain crowds, especially ones where I am expected to participate. However, this can include just being in busy public places like the grocery store, where I may choose to shop during slow times or armed with headphones to block out stuff. At church, the sound of all the voices talking at once afterwards is very overwhelming, and I have a sort of instinctual "flight" response to leave ASAP.
It's really a matter of threshold, for which I think I may have a lower one than many people. I thought this was more about introversion than anything....