Autonomus Sensory Meridian Response (ASMR) is a peculiar condition in which a stimulus (a particular sound, for example) can produce an (often pleasurable) sensation along peripheral regions of the body (back, arms, scalp, etc). It's on the edge of scientific inquiry right now, meaning it is difficult to confirm scientifically. In this way, it's much like synesthesia (and I reckon it's a closely related phenomenon), although synesthesia is much easier to quantify since we've been studying it much more carefully for the past 20-30 years.
So, to put it another way, have you ever been listening to something, and suddenly you get a 'tingling' sensation in your head? Maybe you've heard a noise that sends 'shivers' down your spine. Perhaps the last time someone whispered around you, it caused a similar reaction. Are you able to create these sensations on your own, without the outside stimulus? That's also part of this condition.
I think, however, that this doesn't accurately sum up the entirety of the situation. For example, has anyone ever pointed a pencil (or other pointed object, perhaps a finger) between your eyes, and you feel an actual presence against the bridge of your nose/forehead? I think that this might be an easy test, as I know from experience that most people do indeed have some degree of this feeling. I used to perform this experiment in school, asking people if I could point between their eyes and seeing what response it presented. Not everyone seems to experience it, but most people do.
Thinking back, I recall one other time that I can distinctly express as being this sort of experience. Every day during a particular school period, I would have a class with a person. This person one day decided to start chewing a new brand of gum. The gum was some kind of mint (wintergreen mix perhaps), but the smell wasn't what got me. Before my brain even registered the smell, my teeth would start to hurt for some reason. It made absolutely no sense, as mint was (and still is) one of my favorite things in the world. I don't chalk this up to simple coincidence either, as this was when I was certainly old enough to realize it. I even asked for a stick of the gum, so I could smell it, and surely enough whatever specific smell it was releasing (perhaps there was an underlying smell produced by some other additive, I don't know - it's been over 10 years now) caused my teeth to ache fiercely.
But as of yet, there is no known way to test for ASMR, because it's indicators appear to vary greatly between individuals. As I've suggested above, I think a good method of test would involve things like the finger/eye association. I propose further that, perhaps, ASMR is even a more basic function in general. Have you ever felt like you were falling/moving as a video you were watching accelerated, causing that sensation in the pit of your gut like you're about to hit the ground really fast?
This brings us to the other part of this tale, misophonia. Misophonia can be thought of as noises (and it's almost exclusively noises) that can cause you to be as angry as if someone just punched you in the face, or ran over your dog twice. If you've ever heard a noise that literally makes you want to hit something, or causes you a great deal of anger or distress, or makes you as uncomfortable as a splinter in your toe, then you've experienced misophonia.
If you've ever heard nails on a chalkboard, and it's cause you to immediately want to stop it, but it also causes those chills to run down your spine (or through your skull, etc), then I think it's safe to say you've probably experienced both things. I think this sort of thing could also provide another interesting test into the middle ground that probably links the two conditions.
Unlike ASMR, the DSM now suggests diagnostic criteria for misophonia, although it's a really targeted list that probably doesn't include most of the triggers for misophonia. I am going to say at this point that I think there's a milder form of misophonia, of which perhaps I am afflicted, whereby hearing a particular type of music for an extended period of time (and sometimes almost instantly) can cause me this sort of annoyance.
Imagine for a moment that you haven't used the bathroom for a while, and you've been drinking a lot of water. Suddenly, the urge hits and you need to pee. However, you can't just yet for whatever reason. Slowly, the discomfort builds up, but you tolerate it because you have to. What started as a minor inconvenience/annoyance is now built into something you can no longer ignore. The line for the bathroom is long, and you're getting more aggravated, and you simply can't go anywhere else. It's not a great comparison, but I think it's adequate for illustrating the point.
It's for a similar reason that I don't like the kinds of music I don't like, for example. A song or two that I simply don't like is like that initial urge. It's not a bad thing per se, barely even noticeable perhaps. A few more songs go by, and you notice you just aren't in a good mood like you were an hour ago. After eight hours on the shift, however, little things start to annoy you, things you hadn't so much as noticed before. All these songs are one type of song, similar timing, major keys, similar tempo, all autotuned, whatever it is. It starts to dig at your mind like a splinter digs at your foot. What was a minor irritation to begin with is now an inflamed thing.
Leaving the annoyance is a relief exactly like that of removing a splinter, or using the bathroom, or stopping any kind of pain. It can create the ASMR-like experience of pleasure, like a load lifted from one's shoulders. In this way, I think misophonia works also, not just as an immediate response to a stimulus, but it can also build up over time. Songs I normally wouldn't care about, or perhaps even enjoy to some extent, become like the thought of getting another splinter. A glass of water can be refreshing by itself, but 8 hours of drinking water with no pee breaks might just make you angry at the water, and might just cause you pain.
If you enjoyed reading this, leave a comment below! Even if you didn't enjoy it, let me know your thoughts.