Some people are not capable of experiencing the soothing sensations from ASMR. They will just find them weird, annoying and/or even downright uncomfortable.
I generally cant predict which ASMR videos that will trigger the sensations for me. I mostly go for whispers, hand sounds, gentle mouth sounds and eating sounds, which from experience is my triggers, BUT it is not just about the sound, but very much about the person doing the ASMR. Some ASMR artists who do the mentioned sounds, don't do nothing for me, but when you find that artist that hits the sweet spot. Damn! The sensation is incredible... a waaaarm, slightly tingly, buzzy sensation running through my body and mostly into my head.
Even better then any benzo or alcohol. I think this is the sensation that some drugs might give you, but ASMR is 0% harmful, soooo... It's a drug triggered by our own body's.
Just like with drugs one can develop tolerance to ASMR if used to often though. I generally have some favorite videos I go back to, but sometimes I have to take a break from one video because it will lose its effect. Usually it comes back though, but I am often on the outlook for new favorite videos, as the new ones gives of the strongest sensations... the sensations do wear of a bit over time when you've watched a particular video enough times... well, it does for me at least.
I listen only on speakers and it works fine for me. You don't get sensations with speakers?